feat: navigation clavier et barre de formule dans la visionneuse XLSX #153

A7 : barre de formule sous la barre d'outils (nom de cellule active A1 +
miroir du contenu, édition live, Entrée valide, Échap annule puis
refocalise) ; flèches et Tab déplacent la cellule active dans les 4
directions (Shift inverse Tab), outline persistant sur la cellule active
quand le focus passe à la barre ; Maj+Entrée ne valide plus (réservé au
multiligne A7+). td.tabIndex=0 pour la focalisation clavier.

Vérifié : xlsx-viewer.test.mjs 25/25 (6 nouveaux), E2E 9/9 (barre +
flèches + Échap sur fixture réelle), validate-imports, i18n parity
(xlsx.formula_bar_placeholder, xlsx.active_cell).

🤖 Generated with Codebuff
Co-Authored-By: Codebuff <[email protected]>

CHANGELOG.md

@@ -6,7 +6,7 @@ Format basé sur [Keep a Changelog](https://keepachangelog.com/fr/1.1.0/),
 et [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 > **En cours de développement** : les changements à venir sont listés dans la section
-> [Unreleased](#unreleased). La dernière version livrée est **2.29.0**.
+> [Unreleased](#unreleased). La dernière version livrée est **2.34.0**.
 
 ---
 
@@ -14,6 +14,92 @@ et [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ---
 
+## [2.34.0] — 2026-09-28
+
+---
+
+## [2.33.0] — 2026-09-28
+
+---
+
+## [2.32.0] — 2026-09-28
+
+---
+
+## [2.31.0] — 2026-09-28
+
+### Correction
+
+- **BUG-090 — troncature silencieuse d'une feuille `.xlsx` au-delà de
+  500 lignes × 40 colonnes.** `render_sheets()` renvoie les dimensions
+  déclarées par la feuille (`total_rows`/`total_cols`), les plafonds du
+  moteur (`max_rows`/`max_cols`) et un flag `truncated` : la visionneuse
+  affiche un bandeau « Feuille tronquée — 500 lignes affichées sur 520 »
+  (i18n FR/EN) au lieu de présenter une table courte comme complète. La
+  ligne d'en-têtes est désormais figée au défilement vertical (`thead`
+  sticky, `top: auto` sur les numéros de ligne pour éviter leur
+  empilement en haut à gauche). *#153 A8/R5.*
+
+### Ajouté
+
+- **#153 A9 — chargement paresseux d'une feuille par fenêtres.**
+  `GET /api/file/{vault}/xlsx/sheet?sheet=&offset=&limit=` renvoie un
+  bloc de lignes (`XlsxSheetWindowResponse`, plafond 1 000 lignes par
+  requête, `has_more` de pagination) avec les **vraies** coordonnées A1
+  et numéros de ligne de la feuille — une fenêtre se comporte exactement
+  comme le rendu complet. Erreurs typées : 404 feuille inconnue, 415
+  fichier non-`.xlsx`. La lecture des valeurs calculées en cache (#153
+  A12) s'applique aussi aux fenêtres.
+- **#153 A9bis — « Charger la suite » sous une feuille tronquée.** Un
+  pied de page annonce la progression et fetch la fenêtre suivante au
+  clic ou à l'approche du bas du tableau (sentinelle de défilement).
+  Les lignes ajoutées passent par le même pipeline d'édition que le
+  rendu initial : éditables et sauvegardables immédiatement. Un fetch
+  échoué restore le bouton (retry possible) ; feuille complète → pied
+  de page masqué.
+
+---
+
+## [2.30.0] — 2026-09-27
+
+### Correction
+
+- **BUG-089 — un reindex manuel ne reconstruisait pas l'index inversé.**
+  `reload_index()` / `reload_single_vault()` remplacent l'entrée de vault
+  en bloc, ce qui n'émet pas les notifications incrémentales : la
+  recherche TF-IDF continuait de servir un index périmé après un
+  reindex. Les deux fonctions appellent désormais `init_inverted_index()`.
+  Au passage, `backend/search.py` lisait l'index via
+  `from backend.indexer import index` — une liaison **par valeur** du
+  dict : un rechargement du module `backend.indexer` recréait le dict
+  côté indexer alors que la recherche écrivait dans l'ancien, et
+  l'index inversé n'indexait plus rien. Tous les accès passent par
+  `_indexer.index`. *Trouvé en écrivant le test de recherche d'A5 : il
+  passait isolément et échouait en suite complète selon l'ordre.*
+
+### Ajouté
+
+- **#153 A5 — les tableurs sont indexés par leur contenu.**
+  `extract_indexable_text()` extrait les noms de feuilles et les 20
+  premières lignes (plafond 5 000 caractères, 20 feuilles) pour le
+  TF-IDF et la recherche sémantique. Un mot tapé dans une cellule rend
+  désormais le classeur trouvable ; la lecture binaire pour l'affichage
+  est inchangée et un classeur chiffré/corrompu s'indexe par son seul
+  nom.
+- **#153 A10 — la saisie est typée comme dans Excel.** Une valeur
+  `TRUE`/`FAUX`/`OUI`/`NON` devient un booléen, une date `JJ/MM/AAAA`
+  (avec `HH:MM` optionnel) devient une vraie date — et dans l'ordre
+  français : `01/02/2026` est le 1ᵉʳ février. Une saisie ressemblant à
+  une formule n'est jamais convertie.
+- **#153 A12 — la valeur calculée s'affiche sous la formule.** Quand une
+  cellule porte encore le résultat de son dernier calcul Excel, celui-ci
+  s'affiche dans une ligne discrète sous la formule. La seconde lecture
+  `data_only=True` n'a lieu que si l'archive contient réellement une
+  valeur en cache, et toute erreur retombe sur l'affichage formules seul.
+  Info-bulle traduite FR/EN (`xlsx.cached_value_title`).
+
+---
+
 ## [2.29.0] — 2026-09-27
 
 ### Correction

README.fr.md

@@ -4,7 +4,7 @@
 
 **Porte d'entrée web ultra-léger pour vos vaults Obsidian** — Accédez, naviguez et recherchez dans toutes vos notes Obsidian depuis n'importe quel appareil via une interface web moderne et responsive.
 
-[![Version](https://img.shields.io/badge/Version-2.29.0-blue.svg)]()
+[![Version](https://img.shields.io/badge/Version-2.34.0-blue.svg)]()
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![Docker](https://img.shields.io/badge/Docker-Ready-blue.svg)](https://www.docker.com/)
 [![Python](https://img.shields.io/badge/Python-3.11+-green.svg)](https://www.python.org/)
@@ -976,8 +976,8 @@ Ce projet est sous licence **MIT** — voir le fichier [LICENSE](LICENSE) pour l
 
 ## 📝 Changelog
 
-Consultez le [CHANGELOG.md](./CHANGELOG.md) pour l'historique complet de toutes les versions (v1.0.0 → v2.29.0).
+Consultez le [CHANGELOG.md](./CHANGELOG.md) pour l'historique complet de toutes les versions (v1.0.0 → v2.34.0).
 
 ---
 
-*Projet : ObsiGate | Version : 2.29.0 | Dernière mise à jour : Septembre 2026*
+*Projet : ObsiGate | Version : 2.34.0 | Dernière mise à jour : Septembre 2026*

README.md

@@ -2,7 +2,7 @@
 
 **Ultra-light web gateway for your Obsidian vaults** — Access, browse, and search all your Obsidian notes from any device via a modern, responsive web interface.
 
-[![Version](https://img.shields.io/badge/Version-2.29.0-blue.svg)]()
+[![Version](https://img.shields.io/badge/Version-2.34.0-blue.svg)]()
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![Docker](https://img.shields.io/badge/Docker-Ready-blue.svg)](https://www.docker.com/)
 [![Python](https://img.shields.io/badge/Python-3.11+-green.svg)](https://www.python.org/)
@@ -1151,8 +1151,8 @@ This project is licensed under the **MIT License** - see the [LICENSE](LICENSE)
 
 ## 📝 Changelog
 
-See [CHANGELOG.md](./CHANGELOG.md) for the complete version history (v1.0.0 → v2.29.0).
+See [CHANGELOG.md](./CHANGELOG.md) for the complete version history (v1.0.0 → v2.34.0).
 
 ---
 
-*Project: ObsiGate | Version: 2.29.0 | Last updated: September 2026*
+*Project: ObsiGate | Version: 2.34.0 | Last updated: September 2026*

VERSION

@@ -1 +1 @@
-2.29.0
+2.34.0

backend/indexer.py

@@ -351,6 +351,23 @@ def _decompress_excalidraw(compressed: str) -> dict[str, Any] | None:
     return data
 
 
+def extract_xlsx_indexable(file_path: Path) -> str:
+    """Return searchable text for a workbook (#153 A5).
+
+    Lazy wrapper: ``openpyxl`` is only imported when a spreadsheet is actually
+    indexed, so a vault without workbooks never pays the import. Errors are
+    swallowed — a corrupt or encrypted file still gets indexed by name.
+    """
+    try:
+        from backend.xlsx_reader import extract_indexable_text
+    except Exception:  # pragma: no cover - openpyxl missing
+        return ""
+    try:
+        return extract_indexable_text(file_path)
+    except Exception:  # pragma: no cover - defensive
+        return ""
+
+
 def extract_excalidraw_indexable(raw: str) -> str:
     """Return indexable text content for a raw .excalidraw / .excalidraw.md file.
 
@@ -561,11 +578,12 @@ def _scan_vault(
                     title = fpath.stem.replace("-", " ").replace("_", " ")
                     content_preview = ""
                 elif ext == ".xlsx":
-                    # #152 — binary workbook: metadata only, the viewer renders
-                    # it (parity with _index_single_file_sync).
-                    raw = ""
+                    # #153 A5 — a workbook stays rendered by the viewer, but its
+                    # cell values are now indexed as text so a spreadsheet is
+                    # findable by its content (parity with _index_single_file_sync).
+                    raw = extract_xlsx_indexable(fpath)
                     title = fpath.stem.replace("-", " ").replace("_", " ")
-                    content_preview = ""
+                    content_preview = raw[:200].strip()
                 else:
                     raw = fpath.read_text(encoding="utf-8", errors="replace")
                     title = fpath.stem.replace("-", " ").replace("_", " ")
@@ -807,6 +825,13 @@ async def reload_index() -> dict[str, Any]:
     await build_index()
     # BUG-040/#86: complete the deferred PDF + excalidraw extraction.
     await enrich_pdf_texts()
+    # The inverted index is NOT updated by the hooks here: the rebuild above
+    # replaces whole vault entries, so the incremental notifications are not
+    # emitted for the files that only changed content. Without this, a manual
+    # reindex left TF-IDF search serving a stale index (BUG-089).
+    from backend.search import init_inverted_index
+
+    init_inverted_index()
     stats = {}
     for name, data in index.items():
         stats[name] = {"file_count": len(data["files"]), "tag_count": len(data["tags"])}
@@ -882,6 +907,13 @@ async def reload_single_vault(vault_name: str) -> dict[str, Any]:
     # BUG-040/#86: complete the deferred PDF + excalidraw extraction.
     await enrich_pdf_texts(vault_name)
 
+    # Same as reload_index: the vault entry was replaced wholesale, so rebuild
+    # the inverted index or TF-IDF search keeps serving stale postings
+    # (BUG-089).
+    from backend.search import init_inverted_index
+
+    init_inverted_index()
+
     stats = {"file_count": len(vault_data["files"]), "tag_count": len(vault_data["tags"])}
     logger.info(f"Vault '{vault_name}' reindexed: {stats['file_count']} files, {stats['tag_count']} tags")
     return stats
@@ -955,9 +987,9 @@ def _index_single_file_sync(vault_name: str, vault_path: str, file_path: str, va
             raw = ""
             content_preview = ""
         elif ext == ".xlsx":
-            # #152 — binary workbook: metadata only (parity with _scan_vault).
-            raw = ""
-            content_preview = ""
+            # #153 A5 — index sheet names + header rows as text (see _scan_vault).
+            raw = extract_xlsx_indexable(fpath)
+            content_preview = raw[:200].strip()
         else:
             raw = fpath.read_text(encoding="utf-8", errors="replace")
             content_preview = raw[:200].strip()

backend/openapi_docs.py

@@ -185,6 +185,26 @@ _ENDPOINT_EXAMPLES: dict[tuple[str, str], dict[str, Any]] = {
         "request": {"sheet": "Budget", "cells": {"B1": "250"}, "allow_formula": False, "force": False},
         "response": {"status": "ok", "vault": "TestVault", "path": "data/budget.xlsx", "size": 1},
     },
+    # GET : pas d'exemple de requête (un requestBody sur un GET serait un OpenAPI
+    # invalide) — les paramètres sont documentés par leurs Query().
+    ("get", "/api/file/{vault_name}/xlsx/sheet"): {
+        "response": {
+            "vault": "TestVault",
+            "path": "data/budget.xlsx",
+            "sheet": "Budget",
+            "offset": 0,
+            "limit": 200,
+            "rows": 2,
+            "cols": 2,
+            "total_rows": 640,
+            "total_cols": 12,
+            "max_rows": 500,
+            "max_cols": 40,
+            "truncated": True,
+            "has_more": True,
+            "html": "<table>…</table>",
+        },
+    },
     ("post", "/api/search/replace"): {
         "request": {"query": "Python", "replacement": "Python 3", "vault": "all", "dry_run": True},
         "response": {"matches": [{"vault": "TestVault", "path": "note1.md", "title": "Python", "match_count": 3}], "total_matches": 3, "dry_run": True},

backend/routers/files_read.py

@@ -38,6 +38,7 @@ from backend.schemas import (
     BrowseResponse,
     FileContentResponse,
     FileRawResponse,
+    XlsxSheetWindowResponse,
 )
 from backend.services.files import read_raw_file
 from backend.services.paths import resolve_safe_path
@@ -178,6 +179,71 @@ async def api_file_backlinks(
     }
 
 
+@router.get(
+    "/api/file/{vault_name}/xlsx/sheet", response_model=XlsxSheetWindowResponse
+)
+def api_file_xlsx_sheet(
+    vault_name: str,
+    path: str = Query(..., description="Relative path to the .xlsx file"),
+    sheet: str = Query(..., description="Sheet name (as shown in the viewer tab)"),
+    offset: int = Query(0, ge=0, description="0-based index of the first row to return"),
+    limit: int = Query(
+        200, ge=1, le=1000, description="Rows to return (server-capped)"
+    ),
+    current_user=Depends(require_auth),
+):
+    """Return a window of rows of one sheet of an .xlsx workbook (#153 A9).
+
+    Backs the viewer's lazy loading: instead of every sheet in a single JSON
+    payload, the client asks for the block it is about to display. The row
+    numbers and the ``data-cell`` references are the real A1 coordinates of the
+    sheet, so a window behaves like the full render (editing a cell in it
+    targets the right cell).
+
+    The response also carries ``total_rows``/``total_cols`` and the ``truncated``
+    flag, so the client can say what is hidden behind the 500x40 render caps
+    instead of silently hiding it.
+
+    Args:
+        vault_name: Name of the vault.
+        path: Relative path of the .xlsx file within the vault.
+        sheet: Sheet name; **404** if the workbook has no such sheet.
+        offset: 0-based index of the first row to return.
+        limit: Rows to return, capped server-side at 1000.
+
+    Returns:
+        ``XlsxSheetWindowResponse`` with the rendered ``html`` of the window.
+
+    Raises:
+        HTTPException: 403 (vault access), 404 (vault, file or sheet unknown),
+            415 (not an .xlsx file), 500 (unreadable workbook).
+    """
+    if not check_vault_access(vault_name, current_user):
+        raise HTTPException(status_code=403, detail=f"Accès refusé à la vault '{vault_name}'")
+    vault_data = get_vault_data(vault_name)
+    if not vault_data:
+        raise HTTPException(status_code=404, detail=f"Vault '{vault_name}' not found")
+
+    file_path = resolve_safe_path(Path(vault_data["path"]), path)
+    if not file_path.is_file():
+        raise HTTPException(status_code=404, detail=f"File not found: {path}")
+    if file_path.suffix.lower() != ".xlsx":
+        raise HTTPException(status_code=415, detail="Le fichier n'est pas un classeur .xlsx")
+
+    # Import tardif : openpyxl n'est chargé que si un .xlsx est réellement demandé.
+    from backend.xlsx_reader import read_sheet_window
+
+    try:
+        window = read_sheet_window(file_path, sheet, offset=offset, limit=limit)
+    except Exception as e:
+        logger.error(f"XLSX sheet read error for {path}: {e}")
+        raise HTTPException(status_code=500, detail=f"Error reading XLSX: {e!s}")
+    if window is None:
+        raise HTTPException(status_code=404, detail=f"Feuille introuvable: {sheet}")
+
+    return {"vault": vault_name, "path": path, **window}
+
+
 @router.get("/api/file/{vault_name}", response_model=FileContentResponse)
 async def api_file(vault_name: str, path: str = Query(..., description="Relative path to file"), current_user=Depends(require_auth)):
     """Return rendered HTML and metadata for a file.

backend/schemas.py

@@ -286,7 +286,12 @@ class FileContentResponse(BaseModel):
     is_csv: bool | None = Field(default=None, description="True for CSV files")
     is_xlsx: bool | None = Field(default=None, description="True for Excel .xlsx files")
     xlsx_sheets: list[dict[str, Any]] | None = Field(
-        default=None, description="Rendered xlsx sheets [{name, html}]"
+        default=None,
+        description=(
+            "Rendered xlsx sheets [{name, html, rows, cols, total_rows, "
+            "total_cols, max_rows, max_cols, truncated}] — `truncated` is true "
+            "when the sheet exceeds the 500x40 render caps (#153 A8)"
+        ),
     )
     xlsx_lossy_features: list[str] | None = Field(
         default=None,
@@ -305,6 +310,32 @@ class FileContentResponse(BaseModel):
     image_mime: str | None = Field(default=None, description="MIME type for image files")
 
 
+class XlsxSheetWindowResponse(BaseModel):
+    """One window of rows of a single .xlsx sheet (lazy loading, #153 A9).
+
+    Served by ``GET /api/file/{vault_name}/xlsx/sheet``; the row numbers and
+    the ``data-cell`` references in ``html`` are the real A1 coordinates of the
+    sheet, whatever the window.
+    """
+
+    vault: str = Field(description="Vault name")
+    path: str = Field(description="Relative file path within the vault")
+    sheet: str = Field(description="Sheet name (as shown in the tab)")
+    offset: int = Field(description="0-based index of the first returned row")
+    limit: int = Field(description="Maximum number of rows returned (capped server-side)")
+    rows: int = Field(description="Rows actually returned in this window")
+    cols: int = Field(description="Columns of the rendered window")
+    total_rows: int = Field(description="Rows the sheet declares")
+    total_cols: int = Field(description="Columns the sheet declares")
+    max_rows: int = Field(description="Row cap of the renderer (500) — the coverage of this window")
+    max_cols: int = Field(description="Column cap of the renderer (40)")
+    truncated: bool = Field(
+        description="True when the sheet exceeds the 500x40 render caps"
+    )
+    has_more: bool = Field(description="True when rows remain after this window")
+    html: str = Field(description="Rendered HTML table for the window")
+
+
 class FileRawResponse(BaseModel):
     """Raw text content of a file."""
 

backend/search.py

@@ -12,7 +12,12 @@ from sortedcontainers import SortedList
 
 from backend import indexer as _indexer
 from backend import semantic_search as _semantic
-from backend.indexer import index
+
+# NOTE: the shared index is read through ``_indexer.index`` everywhere, never
+# via ``from backend.indexer import index``. That import binds the dict object
+# once, so a module reload of ``backend.indexer`` (tests, dev reload) rebinds
+# the module-level name to a FRESH dict while this module keeps writing to the
+# stale one — the inverted index then silently indexes nothing (BUG-089).
 from backend.services.regex_safety import (
     MAX_REGEX_MATCHES,
     truncate_for_regex,
@@ -399,7 +404,7 @@ class InvertedIndex:
         self.vault_docs = defaultdict(set)
         self.tag_docs = defaultdict(set)
 
-        for vault_name, vault_data in index.items():
+        for vault_name, vault_data in _indexer.index.items():
             for file_info in vault_data.get("files", []):
                 doc_key = f"{vault_name}::{file_info['path']}"
                 self.doc_count += 1
@@ -688,7 +693,7 @@ _indexer.set_index_change_hook(_on_index_change_hook)
 
 def init_inverted_index():
     """Force initial inverted index build. Called after build_index completes on startup."""
-    if any(vdata.get("files") for vdata in index.values()):
+    if any(vdata.get("files") for vdata in _indexer.index.values()):
         _inverted_index.rebuild()
         logger.info("Inverted index initialized.")
 
@@ -784,7 +789,7 @@ def search(
     else:
         candidates = [
             (vault_name, file_info)
-            for vault_name, vault_data in index.items()
+            for vault_name, vault_data in _indexer.index.items()
             if vault_filter == "all" or vault_name == vault_filter
             for file_info in vault_data["files"]
         ]
@@ -1613,7 +1618,7 @@ def get_all_tags(vault_filter: str | None = None) -> dict[str, int]:
         Dict mapping tag names to their total occurrence count.
     """
     merged: dict[str, int] = {}
-    for vault_name, vault_data in index.items():
+    for vault_name, vault_data in _indexer.index.items():
         if vault_filter and vault_filter != "all" and vault_name != vault_filter:
             continue
         for tag, count in vault_data.get("tags", {}).items():

backend/services/mutations.py

@@ -19,6 +19,7 @@ import shutil
 import threading
 from collections.abc import Callable, Iterator
 from contextlib import contextmanager
+from datetime import date, datetime
 from pathlib import Path
 from typing import Any
 
@@ -237,6 +238,14 @@ _XLSX_FLOAT_RE = re.compile(r"^[+-]?(?:\d+\.\d*|\.\d+)$")
 # the legacy Lotus-style trigger. "+"/"-" are left alone: they are numbers here.
 _XLSX_FORMULA_RE = re.compile(r"^[=@]")
 
+# #153 A10 — types recognised when a user types into a cell. Excel infers them
+# too; storing everything as text would make a spreadsheet unusable (a boolean
+# column stays a string, a date column sorts lexicographically).
+_XLSX_TRUE_LITERALS = {"true", "vrai", "oui", "yes"}
+_XLSX_FALSE_LITERALS = {"false", "faux", "non", "no"}
+# Shape check before strptime: keeps the hot path free of format attempts.
+_XLSX_DATE_RE = re.compile(r"^\d{1,2}[-/]\d{1,2}[-/]\d{4}(?:[ T]\d{1,2}:\d{2})?$")
+
 # #153 A3 — per-file write lock. Two concurrent saves (two tabs, the AI agent
 # and the viewer, a watcher restore) would otherwise read-modify-write on the
 # same archive and the last writer silently wins. Kept deliberately small: the
@@ -270,7 +279,21 @@ def _xlsx_write_lock(key: str) -> Iterator[None]:
 
 
 def _coerce_xlsx_value(value: Any) -> Any:
-    """Turn the string sent by the cell editor back into a scalar."""
+    """Turn the string sent by the cell editor back into a scalar (#153 A10).
+
+    The coercion is symmetric with :func:`backend.xlsx_reader._fmt`: a value
+    typed by the user comes back as a string, and Excel would have inferred a
+    type when typing the same thing. Recognised here:
+
+    * an empty cell -> ``None`` (clears it)
+    * ``1234`` / ``-1`` -> ``int``
+    * ``1.5`` / ``.5`` -> ``float``
+    * ``TRUE``/``FAUX`` (case-insensitive) -> ``bool``
+    * ``31/12/2026`` / ``31/12/2026 14:30`` -> ``date``/``datetime`` (FR)
+
+    Anything else stays text. A date-looking string typed with a leading
+    ``=`` is a formula and never reaches here as a date.
+    """
     if not isinstance(value, str):
         return value
     text = value.strip()
@@ -280,9 +303,35 @@ def _coerce_xlsx_value(value: Any) -> Any:
         return int(text)
     if _XLSX_FLOAT_RE.match(text):
         return float(text)
+    lowered = text.lower()
+    if lowered in _XLSX_TRUE_LITERALS:
+        return True
+    if lowered in _XLSX_FALSE_LITERALS:
+        return False
+    if not _XLSX_FORMULA_RE.match(text):
+        parsed = _parse_fr_datetime(text)
+        if parsed is not None:
+            return parsed
     return value
 
 
+def _parse_fr_datetime(text: str) -> date | datetime | None:
+    """Parse a FR-localised date/datetime, or return ``None``.
+
+    Accepts ``JJ/MM/AAAA`` and ``JJ/MM/AAAA HH:MM`` (also ``JJ-MM-AAAA``).
+    ``dayfirst`` is what makes ``01/02/2026`` the 1st of February rather than
+    the 2nd of January — the French convention.
+    """
+    if not _XLSX_DATE_RE.match(text):
+        return None
+    for fmt in ("%d/%m/%Y %H:%M", "%d/%m/%Y", "%d-%m-%Y %H:%M", "%d-%m-%Y"):
+        try:
+            return datetime.strptime(text, fmt)
+        except ValueError:
+            continue
+    return None
+
+
 def _write_cell(ws: Any, ref: str, value: Any, *, allow_formula: bool) -> None:
     """Assign one cell, forcing text when it looks like a formula.
 

backend/tools/api.py

@@ -13,6 +13,7 @@ from backend.tools import connected as _connected  # noqa: F401  (registers conn
 from backend.tools import crawler as _crawler  # noqa: F401  (registers the site crawler)
 from backend.tools import documents as _documents  # noqa: F401  (registers document tools)
 from backend.tools import service as _service  # noqa: F401  (registers tools)
+from backend.tools import spreadsheets as _spreadsheets  # noqa: F401  (registers existing-workbook tools #153 A6)
 from backend.tools import web as _web  # noqa: F401  (registers web tools)
 from backend.tools.context import (
     ToolConfirmationRequired,

backend/tools/labels.py

@@ -52,6 +52,10 @@ _STEP_LABELS: dict[str, tuple[str, str | None]] = {
     "git_search_issues": ("git_issues", "query"),
     "git_get_file": ("git_file", "path"),
     "create_xlsx": ("xlsx_create", "path"),
+    "list_xlsx_sheets": ("xlsx_sheets", "path"),
+    "xlsx_to_markdown": ("xlsx_read", "path"),
+    "update_xlsx_cells": ("xlsx_update", "path"),
+    "append_xlsx_rows": ("xlsx_append", "path"),
     "create_docx": ("docx_create", "path"),
     "create_csv": ("csv_create", "path"),
     "create_pdf": ("pdf_create", "path"),

backend/tools/schemas.py

@@ -315,6 +315,61 @@ class DocxInput(BaseModel):
     overwrite: bool = Field(True, description="Replace an existing file (with backup)")
 
 
+class ListXlsxSheetsInput(BaseModel):
+    """List the sheets of an existing .xlsx workbook (#153 A6)."""
+
+    vault: str = Field(..., description="Vault name")
+    path: str = Field(..., description="Vault-relative path of the .xlsx file")
+
+
+class XlsxToMarkdownInput(BaseModel):
+    """Read one sheet of an existing .xlsx workbook as markdown (#153 A6)."""
+
+    vault: str = Field(..., description="Vault name")
+    path: str = Field(..., description="Vault-relative path of the .xlsx file")
+    sheet: str = Field(
+        "", description="Sheet name (empty = the first/active sheet)"
+    )
+
+
+class UpdateXlsxCellsInput(BaseModel):
+    """Batch-edit cells of an existing .xlsx workbook (#153 A6)."""
+
+    vault: str = Field(..., description="Vault name")
+    path: str = Field(..., description="Vault-relative path of the .xlsx file")
+    sheet: str = Field(..., description="Worksheet title to edit")
+    cells: dict[str, str | int | float | bool | None] = Field(
+        ..., description="A1 reference -> new value (max 500 per call)"
+    )
+    allow_formula: bool = Field(
+        False,
+        description="Store '='/'@' values as real formulas (off by default, DDE guard)",
+    )
+    force: bool = Field(
+        False,
+        description="Write even when features openpyxl cannot rewrite would be dropped",
+    )
+
+
+class AppendXlsxRowsInput(BaseModel):
+    """Append rows at the end of a sheet of an existing .xlsx (#153 A6)."""
+
+    vault: str = Field(..., description="Vault name")
+    path: str = Field(..., description="Vault-relative path of the .xlsx file")
+    sheet: str = Field(..., description="Worksheet title to extend")
+    rows: list[list[str | int | float | bool | None]] = Field(
+        ..., description="Rows of cell values, appended below the last used row (max 500)"
+    )
+    allow_formula: bool = Field(
+        False,
+        description="Store '='/'@' values as real formulas (off by default, DDE guard)",
+    )
+    force: bool = Field(
+        False,
+        description="Write even when features openpyxl cannot rewrite would be dropped",
+    )
+
+
 class CsvInput(BaseModel):
     """Create a .csv file in a vault from rows of cells."""
 

backend/tools/spreadsheets.py

@@ -0,0 +1,286 @@
+"""Spreadsheet tools (#153 A6) — read and mutate existing ``.xlsx`` workbooks.
+
+Complements :mod:`backend.tools.documents` (``create_xlsx`` creates a *new*
+file; here the assistant can read and edit one that already exists):
+
+* ``list_xlsx_sheets``  — READ, sheet names + dimensions;
+* ``xlsx_to_markdown``  — READ, bounded markdown table for the LLM context;
+* ``update_xlsx_cells`` — WRITE, batch cell edits (wraps the guarded service);
+* ``append_xlsx_rows``  — WRITE, append whole rows at the end of a sheet.
+
+Mutation tools go through :func:`backend.services.mutations.edit_xlsx_cells`,
+which already carries the #153 P0 guards: per-file lock, atomic replace,
+formula neutralisation (``allow_formula`` opt-in) and the lossy-write 409.
+"""
+
+from __future__ import annotations
+
+import logging
+from pathlib import Path
+from typing import Any
+
+from backend.services.errors import ServiceError
+from backend.services.paths import resolve_safe_path
+from backend.services.vaults import get_vault_root
+from backend.tools.context import ToolContext, ToolError, ToolRisk
+from backend.tools.registry import tool
+from backend.tools.schemas import (
+    AppendXlsxRowsInput,
+    ListXlsxSheetsInput,
+    UpdateXlsxCellsInput,
+    XlsxToMarkdownInput,
+)
+
+logger = logging.getLogger("obsigate.tools.spreadsheets")
+
+# xlsx_to_markdown ceiling: a workbook is a data dump, not prose. The table is
+# for the LLM context, so both axes are bounded (same spirit as A5's index cap).
+MAX_MD_ROWS = 100
+MAX_MD_COLS = 20
+MAX_MD_CHARS = 20_000
+
+
+def _workbook_path(vault: str, path: str) -> Path:
+    """Resolve and validate a vault-relative ``.xlsx`` path."""
+    path = (path or "").strip()
+    if not path.lower().endswith(".xlsx"):
+        raise ToolError("Extension attendue : .xlsx", code="invalid_arguments")
+    try:
+        root = get_vault_root(vault)
+    except ServiceError as e:
+        raise ToolError(e.message, code=e.code, details=e.details) from e
+    return resolve_safe_path(root, path)
+
+
+def _map_service_error(e: ServiceError) -> ToolError:
+    return ToolError(e.message, code=e.code, details=e.details)
+
+
+@tool(
+    name="list_xlsx_sheets",
+    description=(
+        "List the sheets of an .xlsx workbook with their dimensions "
+        "(rows x columns) and whether the display caps truncate them. "
+        "Use before editing to pick the right sheet name."
+    ),
+    input_model=ListXlsxSheetsInput,
+    risk=ToolRisk.READ,
+    requires_vault=True,
+)
+def list_xlsx_sheets(ctx: ToolContext, params: ListXlsxSheetsInput) -> dict[str, Any]:
+    """Return sheet names and extents of the workbook."""
+    from backend.xlsx_reader import MAX_COLS, MAX_ROWS, _sheet_extent
+
+    file_path = _workbook_path(params.vault, params.path)
+    try:
+        from openpyxl import load_workbook
+
+        wb = load_workbook(str(file_path), read_only=True, data_only=True)
+    except ServiceError as e:
+        raise _map_service_error(e) from e
+    except Exception as e:
+        raise ToolError(f"Classeur illisible: {e}", code="invalid") from e
+    try:
+        sheets = []
+        for ws in wb.worksheets:
+            total_rows, total_cols = _sheet_extent(ws)
+            sheets.append(
+                {
+                    "name": ws.title,
+                    "total_rows": total_rows,
+                    "total_cols": total_cols,
+                    "truncated": total_rows > MAX_ROWS or total_cols > MAX_COLS,
+                }
+            )
+        return {"vault": params.vault, "path": params.path, "sheets": sheets}
+    finally:
+        wb.close()
+
+
+@tool(
+    name="xlsx_to_markdown",
+    description=(
+        "Read a sheet of an .xlsx workbook as a bounded markdown table "
+        "(up to 100 rows x 20 columns). Use to inspect spreadsheet data "
+        "before answering or editing."
+    ),
+    input_model=XlsxToMarkdownInput,
+    risk=ToolRisk.READ,
+    requires_vault=True,
+)
+def xlsx_to_markdown(ctx: ToolContext, params: XlsxToMarkdownInput) -> dict[str, Any]:
+    """Render one sheet as a markdown table for the LLM context."""
+    from openpyxl import load_workbook
+
+    from backend.xlsx_reader import _fmt
+
+    file_path = _workbook_path(params.vault, params.path)
+    try:
+        wb = load_workbook(str(file_path), read_only=True, data_only=True)
+    except ServiceError as e:
+        raise _map_service_error(e) from e
+    except Exception as e:
+        raise ToolError(f"Classeur illisible: {e}", code="invalid") from e
+    try:
+        if params.sheet:
+            if params.sheet not in wb.sheetnames:
+                raise ToolError(
+                    f"Feuille introuvable: {params.sheet}", code="not_found"
+                )
+            ws = wb[params.sheet]
+        else:
+            ws = wb.active
+        title = ws.title
+        rows: list[list[str]] = []
+        truncated = False
+        for row in ws.iter_rows(
+            min_row=1, max_row=MAX_MD_ROWS, max_col=MAX_MD_COLS, values_only=True
+        ):
+            cells = [_fmt(v) for v in row]
+            if not any(c.strip() for c in cells):
+                continue
+            rows.append(cells)
+        # Real tail beyond the caps? Probe one row further.
+        probe = list(
+            ws.iter_rows(
+                min_row=MAX_MD_ROWS + 1,
+                max_row=MAX_MD_ROWS + 1,
+                max_col=MAX_MD_COLS,
+                values_only=True,
+            )
+        )
+        if any(any(str(v or "").strip() for v in r) for r in probe):
+            truncated = True
+    finally:
+        wb.close()
+
+    lines: list[str] = []
+    if rows:
+        header = rows[0]
+        lines.append("| " + " | ".join(header) + " |")
+        lines.append("|" + "|".join("---" for _ in header) + "|")
+        for row in rows[1:]:
+            lines.append("| " + " | ".join(row) + " |")
+    table = "\n".join(lines)[:MAX_MD_CHARS]
+
+    return {
+        "vault": params.vault,
+        "path": params.path,
+        "sheet": title,
+        "rows": len(rows),
+        "cols": max((len(r) for r in rows), default=0),
+        "truncated": truncated,
+        "markdown": table,
+    }
+
+
+@tool(
+    name="update_xlsx_cells",
+    description=(
+        "Edit cells of an existing .xlsx workbook. ``cells`` maps A1 "
+        "references to new values (max 500). A value starting with '=' or "
+        "'@' is stored as TEXT unless allow_formula is set (DDE guard). "
+        "Editing a workbook carrying features openpyxl cannot rewrite "
+        "requires force=true (cached formula results, slicers…)."
+    ),
+    input_model=UpdateXlsxCellsInput,
+    risk=ToolRisk.WRITE,
+    requires_vault=True,
+)
+def update_xlsx_cells(ctx: ToolContext, params: UpdateXlsxCellsInput) -> dict[str, Any]:
+    """Wrap the guarded cell-edit service."""
+    from backend.services.mutations import edit_xlsx_cells
+
+    if not params.cells:
+        raise ToolError("Aucune cellule fournie", code="invalid_arguments")
+    try:
+        result = edit_xlsx_cells(
+            params.vault,
+            params.path,
+            params.sheet,
+            dict(params.cells),
+            allow_formula=params.allow_formula,
+            force=params.force,
+        )
+    except ServiceError as e:
+        raise _map_service_error(e) from e
+    return {
+        "status": "ok",
+        "vault": result["vault"],
+        "path": result["path"],
+        "sheet": params.sheet,
+        "cells": len(params.cells),
+    }
+
+
+@tool(
+    name="append_xlsx_rows",
+    description=(
+        "Append rows at the end of a sheet of an existing .xlsx workbook. "
+        "Values are typed like in the viewer (numbers, TRUE/FALSE, FR dates "
+        "JJ/MM/AAAA). The workbook is rewritten atomically with a backup."
+    ),
+    input_model=AppendXlsxRowsInput,
+    risk=ToolRisk.WRITE,
+    requires_vault=True,
+)
+def append_xlsx_rows(ctx: ToolContext, params: AppendXlsxRowsInput) -> dict[str, Any]:
+    """Append whole rows below the last used row of the sheet."""
+    from openpyxl import load_workbook
+    from openpyxl.utils import get_column_letter
+
+    from backend.services.mutations import _coerce_xlsx_value, edit_xlsx_cells
+
+    if not params.rows:
+        raise ToolError("Aucune ligne fournie", code="invalid_arguments")
+    if len(params.rows) > 500:
+        raise ToolError("Trop de lignes (max 500)", code="invalid_arguments")
+
+    file_path = _workbook_path(params.vault, params.path)
+    try:
+        wb = load_workbook(str(file_path), read_only=True, data_only=True)
+        try:
+            if params.sheet not in wb.sheetnames:
+                raise ToolError(
+                    f"Feuille introuvable: {params.sheet}", code="not_found"
+                )
+            ws = wb[params.sheet]
+            first_free = (ws.max_row or 0) + 1
+        finally:
+            wb.close()
+    except ServiceError as e:
+        raise _map_service_error(e) from e
+    except ToolError:
+        raise
+    except Exception as e:
+        raise ToolError(f"Classeur illisible: {e}", code="invalid") from e
+
+    cells: dict[str, Any] = {}
+    for i, row in enumerate(params.rows):
+        for j, value in enumerate(row):
+            if value is None or (isinstance(value, str) and not value.strip()):
+                continue
+            ref = f"{get_column_letter(j + 1)}{first_free + i}"
+            cells[ref] = _coerce_xlsx_value(value)
+    if not cells:
+        raise ToolError("Aucune valeur fournie", code="invalid_arguments")
+
+    try:
+        result = edit_xlsx_cells(
+            params.vault,
+            params.path,
+            params.sheet,
+            cells,
+            allow_formula=params.allow_formula,
+            force=params.force,
+        )
+    except ServiceError as e:
+        raise _map_service_error(e) from e
+    return {
+        "status": "ok",
+        "vault": result["vault"],
+        "path": result["path"],
+        "sheet": params.sheet,
+        "rows": len(params.rows),
+        "first_row": first_free,
+    }

backend/xlsx_reader.py

@@ -11,6 +11,7 @@ round-trip would drop (#153 A1) so the UI can warn before saving.
 from __future__ import annotations
 
 import html
+import logging
 import re
 import zipfile
 from datetime import date, datetime
@@ -20,11 +21,19 @@ from typing import Any
 from openpyxl import load_workbook
 from openpyxl.utils import get_column_letter
 
+logger = logging.getLogger("obsigate.xlsx_reader")
+
 # ponytail: hard caps bound the rendered grid (500 rows x 40 cols per sheet).
 # Raise them, or paginate per sheet, if a real workbook needs more.
 MAX_ROWS = 500
 MAX_COLS = 40
 
+# #153 A9 — window size served by ``read_sheet_window()`` (lazy per-sheet
+# loading). The endpoint is bounded so a single request can never ask for the
+# whole workbook back in one JSON payload; the UI pages through the rest.
+MAX_WINDOW_ROWS = 1_000
+DEFAULT_WINDOW_ROWS = 200
+
 # #153 A1 — workbook parts openpyxl does not re-serialize on load+save.
 # Verified against openpyxl 3.1.5: charts, images, drawings and pivot tables
 # DO survive the round-trip, so they are deliberately absent from this map.
@@ -48,6 +57,14 @@ _CACHED_FORMULA_RE = re.compile(rb"<f[ >][^<]*</f>\s*<v>[^<]")
 # Sheet XML scanned by the cached-formula probe (CPU guard, like MAX_REPLACE_FILE_BYTES).
 _MAX_PROBE_BYTES = 8_000_000
 
+# #153 A5 — ceiling on the text handed to the TF-IDF / semantic index. A workbook
+# is a data dump, not prose: indexing every cell would flood the inverted index
+# and bury the notes. Sheet names + the first rows are enough to make a
+# spreadsheet findable by its headers.
+MAX_INDEX_CHARS = 5_000
+_INDEX_ROWS_PER_SHEET = 20
+MAX_INDEX_SHEETS = 20
+
 
 def _fmt(value: Any) -> str:
     if value is None:
@@ -74,7 +91,37 @@ def _trim(grid: list[list[str]]) -> list[list[str]]:
     return [row[:width] for row in grid]
 
 
-def _table(grid: list[list[str]]) -> str:
+def _cell_cached(cached: list[list[str]] | None, r: int, c: int) -> str:
+    """Return the cached result for a 0-based cell, or ``""``.
+
+    The shadow grid is read positionally and may be narrower than the formula
+    grid (``_trim`` collapses the trailing empty columns of each grid
+    independently), so every lookup is bounds-checked rather than assumed.
+    """
+    if not cached or r >= len(cached):
+        return ""
+    row = cached[r]
+    return row[c] if c < len(row) else ""
+
+
+def _table(
+    grid: list[list[str]],
+    cached: list[list[str]] | None = None,
+    row_offset: int = 0,
+) -> str:
+    """Render a grid as an HTML table.
+
+    ``cached`` is the same grid read with ``data_only=True`` (#153 A12): where a
+    formula cell still carries its last computed result, it is shown as a
+    discreet second line (``<span class="xlsx-cached">``) so the user sees the
+    number Excel last calculated instead of only the formula text. The span
+    carries ``data-cached-value`` and is titled client-side from
+    ``xlsx.cached_value_title`` — the backend never emits UI text.
+
+    ``row_offset`` is the number of rows skipped before this grid (#153 A9): the
+    row numbers and the ``data-cell`` references must stay the real A1
+    coordinates of the sheet, not of the window.
+    """
     if not grid:
         return "<p><em>Feuille vide</em></p>"
     n_cols = max(len(row) for row in grid)
@@ -86,11 +133,28 @@ def _table(grid: list[list[str]]) -> str:
     ]
     out += [f"<th>{get_column_letter(c)}</th>" for c in range(1, n_cols + 1)]
     out.append("</tr></thead><tbody>")
-    for r, row in enumerate(grid, start=1):
+    for r, row in enumerate(grid, start=row_offset + 1):
         out.append(f'<tr><th class="xlsx-rownum">{r}</th>')
         for c, val in enumerate(row, start=1):
             ref = f"{get_column_letter(c)}{r}"
-            out.append(f'<td data-cell="{ref}">{html.escape(val)}</td>')
+            # The cached result only makes sense for a formula cell: on a plain
+            # value cell the two reads are identical and showing both would
+            # duplicate the text.
+            shadow = ""
+            if cached is not None and val.startswith("="):
+                # `c` is 1-based (A1 notation) and `r` too, while the grid is
+                # 0-based: translate both.
+                cval = _cell_cached(cached, r - 1, c - 1)
+                if cval and cval != val:
+                    # The tooltip is translated client-side from
+                    # `xlsx.cached_value_title`; never hardcode UI text here.
+                    shadow = (
+                        f'<span class="xlsx-cached" data-cached-value="1">'
+                        f"{html.escape(cval)}</span>"
+                    )
+            out.append(
+                f'<td data-cell="{ref}">{html.escape(val)}{shadow}</td>'
+            )
         out.append("</tr>")
     out.append("</tbody></table></div>")
     return "".join(out)
@@ -141,19 +205,242 @@ def inspect_workbook(file_path: Path) -> list[str]:
         return []
 
 
-def render_sheets(file_path: Path) -> list[dict[str, str]]:
-    """Return ``[{"name": sheet_title, "html": table_html}, ...]``."""
+def render_sheets(file_path: Path) -> list[dict[str, Any]]:
+    """Return one dict per sheet: ``{name, html, rows, cols, total_*, truncated}``.
+
+    Reads the workbook twice: once with ``data_only=False`` for the formulas
+    (what the user must edit) and, when any formula carries a cached result
+    (#153 A12), once with ``data_only=True`` to show what Excel last computed.
+    The second pass is skipped entirely when the archive holds no cached value,
+    so the common case still costs a single load.
+
+    ``total_rows``/``total_cols`` are the dimensions the sheet declares and
+    ``truncated`` says whether the hard caps actually cut it (#153 A8) — the
+    viewer needs both to stop silently hiding the tail of a sheet.
+    """
     wb = load_workbook(str(file_path), read_only=True, data_only=False)
     try:
-        sheets = []
-        for ws in wb.worksheets:
-            grid = [
-                [_fmt(v) for v in row]
-                for row in ws.iter_rows(
-                    min_row=1, max_row=MAX_ROWS, max_col=MAX_COLS, values_only=True
-                )
-            ]
-            sheets.append({"name": ws.title, "html": _table(_trim(grid))})
-        return sheets
+        formulas = [_sheet_grid(ws) for ws in wb.worksheets]
+        titles = [ws.title for ws in wb.worksheets]
+        extents = [_sheet_extent(ws) for ws in wb.worksheets]
     finally:
         wb.close()
+
+    cached: list[list[list[str]]] | None = None
+    if _has_cached_values(file_path):
+        cached = _read_cached_grids(file_path, titles)
+
+    sheets = []
+    for i, title in enumerate(titles):
+        grid = _trim(formulas[i])
+        # The shadow grid is NOT trimmed independently: _trim drops the
+        # trailing empty columns of each grid on its own width, which would
+        # shift every cached value left of its formula. Indexing it
+        # positionally against the untrimmed grid keeps the two aligned.
+        shadow = cached[i] if cached is not None and i < len(cached) else None
+        total_rows, total_cols = extents[i]
+        sheets.append(
+            {
+                "name": title,
+                "html": _table(grid, shadow),
+                "rows": len(grid),
+                "cols": max((len(r) for r in grid), default=0),
+                "total_rows": total_rows,
+                "total_cols": total_cols,
+                # Coverage, not display size: `rows`/`cols` are post-trim (a
+                # sheet of 3 filled cells in a 500-row block renders 1x1), and
+                # the client must announce the cap it stopped at, not how many
+                # cells happen to be non-empty.
+                "max_rows": MAX_ROWS,
+                "max_cols": MAX_COLS,
+                # A sheet is truncated when the caps, not the trailing blanks,
+                # decided its shape: comparing against the *rendered* size would
+                # flag every sheet carrying a few empty formatted rows.
+                "truncated": total_rows > MAX_ROWS or total_cols > MAX_COLS,
+            }
+        )
+    return sheets
+
+
+def read_sheet_window(
+    file_path: Path,
+    sheet: str,
+    offset: int = 0,
+    limit: int = DEFAULT_WINDOW_ROWS,
+) -> dict[str, Any] | None:
+    """Return a window of rows of one sheet, or ``None`` if the sheet is unknown.
+
+    Backs the lazy per-sheet loading of #153 A9: the viewer asks for the rows
+    it is about to display instead of shipping every sheet in the initial file
+    payload. ``offset`` is 0-based; the row numbers and the ``data-cell``
+    references in the returned ``html`` are the real A1 coordinates of the
+    sheet, so a window is indistinguishable from a full render.
+
+    ``limit`` is clamped to :data:`MAX_WINDOW_ROWS`. Raises nothing: an unknown
+    sheet yields ``None`` and a broken workbook propagates the caller's usual
+    500.
+    """
+    offset = max(int(offset), 0)
+    limit = min(max(int(limit), 1), MAX_WINDOW_ROWS)
+
+    wb = load_workbook(str(file_path), read_only=True, data_only=False)
+    try:
+        if sheet not in wb.sheetnames:
+            return None
+        ws = wb[sheet]
+        total_rows, total_cols = _sheet_extent(ws)
+        grid = _trim(
+            _sheet_grid(ws, min_row=offset + 1, max_row=offset + limit)
+        )
+    finally:
+        wb.close()
+
+    shadow: list[list[str]] | None = None
+    # Same A12 rule as the full render: the second read only happens when the
+    # archive really holds cached results.
+    if _has_cached_values(file_path):
+        shadow = _read_cached_window(file_path, sheet, offset, limit)
+    return {
+        "sheet": sheet,
+        "offset": offset,
+        "limit": limit,
+        "rows": len(grid),
+        "cols": max((len(r) for r in grid), default=0),
+        "total_rows": total_rows,
+        "total_cols": total_cols,
+        "max_rows": MAX_ROWS,
+        "max_cols": MAX_COLS,
+        "truncated": total_rows > MAX_ROWS or total_cols > MAX_COLS,
+        "has_more": offset + len(grid) < total_rows,
+        "html": _table(grid, shadow, row_offset=offset),
+    }
+
+
+def _read_cached_window(
+    file_path: Path, sheet: str, offset: int, limit: int
+) -> list[list[str]] | None:
+    """``data_only=True`` grid for one window, or ``None`` if unavailable.
+
+    Best effort like :func:`_read_cached_grids`: a workbook Excel opens but
+    openpyxl cannot re-read must still display (formulas only).
+    """
+    try:
+        wb = load_workbook(str(file_path), read_only=True, data_only=True)
+    except Exception:
+        return None
+    try:
+        if sheet not in wb.sheetnames:
+            return None
+        return _sheet_grid(
+            wb[sheet], min_row=offset + 1, max_row=offset + limit
+        )
+    except Exception:
+        logger.debug("xlsx cached window unavailable", exc_info=True)
+        return None
+    finally:
+        wb.close()
+
+
+def _sheet_extent(ws: Any) -> tuple[int, int]:
+    """Rows and columns the worksheet declares, never negative.
+
+    ``max_row``/``max_column`` come from the sheet's dimension record; a
+    hand-edited file may omit it, hence the defensive coercion.
+    """
+    try:
+        rows = max(int(getattr(ws, "max_row", 0) or 0), 0)
+    except (TypeError, ValueError):
+        rows = 0
+    try:
+        cols = max(int(getattr(ws, "max_column", 0) or 0), 0)
+    except (TypeError, ValueError):
+        cols = 0
+    return rows, cols
+
+
+def _sheet_grid(
+    ws: Any, min_row: int = 1, max_row: int = MAX_ROWS, max_col: int = MAX_COLS
+) -> list[list[str]]:
+    """Read a worksheet window into a grid of formatted strings, bounded by the caps."""
+    return [
+        [_fmt(v) for v in row]
+        for row in ws.iter_rows(
+            min_row=min_row, max_row=max_row, max_col=max_col, values_only=True
+        )
+    ]
+
+
+def _has_cached_values(file_path: Path) -> bool:
+    """True when the archive holds at least one ``<f>…</f><v>…</v>``."""
+    try:
+        with zipfile.ZipFile(file_path) as zf:
+            return _has_cached_formulas(zf)
+    except (OSError, zipfile.BadZipFile):
+        return False
+
+
+def _read_cached_grids(
+    file_path: Path, titles: list[str]
+) -> list[list[list[str]]] | None:
+    """Read every sheet with ``data_only=True`` (what Excel last computed).
+
+    Best effort: returns ``None`` on any failure so the viewer falls back to the
+    formula-only rendering. A workbook Excel opens but openpyxl cannot re-read
+    must still display.
+    """
+    try:
+        wb = load_workbook(str(file_path), read_only=True, data_only=True)
+    except Exception:
+        return None
+    try:
+        grids = [_sheet_grid(ws) for ws in wb.worksheets]
+        if [ws.title for ws in wb.worksheets] != titles:
+            return None
+        return grids
+    except Exception:
+        logger.debug("xlsx cached values unavailable", exc_info=True)
+        return None
+    finally:
+        wb.close()
+
+
+def extract_indexable_text(file_path: Path) -> str:
+    """Return searchable text for the TF-IDF / semantic index (#153 A5).
+
+    Sheet names plus the first :data:`_INDEX_ROWS_PER_SHEET` rows of each
+    sheet, capped at :data:`MAX_INDEX_CHARS`. Rows are tab-joined so a search
+    for a header matches the sheet it belongs to.
+
+    Never raises: a corrupt, encrypted or unsupported workbook yields ``""`` so
+    the file still gets indexed by name (same contract as :func:`inspect_workbook`).
+    """
+    chunks: list[str] = []
+    budget = MAX_INDEX_CHARS
+    try:
+        wb = load_workbook(str(file_path), read_only=True, data_only=True)
+    except Exception:
+        # Encrypted (BadZipFile) or not a real workbook: name-only indexing.
+        return ""
+    try:
+        for ws in wb.worksheets[:MAX_INDEX_SHEETS]:
+            if budget <= 0:
+                break
+            # The sheet title alone is a strong signal ("Recettes", "Budget").
+            block = [ws.title]
+            for row in ws.iter_rows(
+                min_row=1, max_row=_INDEX_ROWS_PER_SHEET, max_col=MAX_COLS, values_only=True
+            ):
+                cells = [_fmt(v) for v in row]
+                # Skip blank rows instead of emitting runs of tabs.
+                if not any(c.strip() for c in cells):
+                    continue
+                block.append("\t".join(cells).rstrip())
+            text = "\n".join(block)
+            chunks.append(text[:budget])
+            budget -= len(text)
+    except Exception:
+        # Truncated but still useful: keep whatever was collected.
+        pass
+    finally:
+        wb.close()
+    return "\n".join(c for c in chunks if c).strip()

desktop/Cargo.lock

@@ -2626,7 +2626,7 @@ dependencies = [
 
 [[package]]
 name = "obsigate-desktop"
-version = "2.29.0"
+version = "2.34.0"
 dependencies = [
  "chrono",
  "env_logger",

desktop/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "obsigate-desktop"
-version = "2.29.0"
+version = "2.34.0"
 description = "ObsiGate Desktop — Porte d'entrée native pour vos vaults Obsidian"
 authors = ["Bruno Charest"]
 edition = "2021"

desktop/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://raw.githubusercontent.com/nicedoc/obsigate/main/desktop/tauri.conf.schema.json",
   "productName": "ObsiGate",
-  "version": "2.29.0",
+  "version": "2.34.0",
   "identifier": "com.obsigate.desktop",
   "build": {
     "frontendDist": "../frontend",

docs/GUIDES/RECHERCHE_PDF_EXCALIDRAW.md

@@ -171,13 +171,38 @@ curl -X PUT "http://localhost:2020/api/file/Recettes/xlsx/save?path=budget.xlsx"
 - Deux sauvegardes simultanées sur le même fichier : la seconde reçoit
   **409** `conflict` au lieu d'écraser la première.
 
+### Feuilles volumineuses et lecture par fenêtres
+
+Le rendu est plafonné à **500 lignes × 40 colonnes** par feuille. Quand
+une feuille dépasse ce plafond, un bandeau **« Feuille tronquée »**
+l'annonce explicitement (par exemple « 500 lignes affichées sur 520 »)
+au lieu de présenter une table courte comme complète — le classeur,
+lui, n'est jamais modifié. La ligne d'en-têtes de colonnes reste
+visible pendant le défilement vertical.
+
+Côté API, `GET /api/file/{vault}/xlsx/sheet` sert une feuille **par
+fenêtres de lignes**, y compris au-delà du plafond d'affichage — les
+coordonnées A1 renvoyées sont celles de la feuille réelle :
+
+```bash
+curl "http://localhost:2020/api/file/Recettes/xlsx/sheet?path=budget.xlsx&sheet=Budget&offset=500&limit=200"
+```
+
+- `offset` : première ligne renvoyée (0-based) ; `limit` : nombre de
+  lignes (1 à 1 000 par requête).
+- La réponse porte `total_rows`, `truncated` et `has_more` pour paginer.
+- Erreurs : **404** si la feuille n'existe pas, **415** si le fichier
+  n'est pas un `.xlsx`.
+
 ### Limites
 
-- Le rendu est plafonné à **500 lignes × 40 colonnes** par feuille, sans
-  pagination : au-delà, le contenu n'est pas affiché (et non éditable).
+- L'affichage intégré démarre à **500 lignes × 40 colonnes** par feuille ;
+  sous une feuille plus grande, le bouton **« Charger la suite »** (ou le
+  défilement vers le bas du tableau) ajoute les lignes suivantes par
+  fenêtres de 500 — elles deviennent aussitôt éditables et
+  sauvegardables.
 - Styles, formats de nombre, cellules fusionnées et volets figés ne sont pas
-  rendus ; le contenu des tableurs n'est pas non plus indexé pour la
-  recherche (contrairement aux PDF).
+  rendus.
 - Formats non gérés : `.xls`, `.xlsm` (macros), `.ods`.
 
 ---

docs/ISSUES_TODOLIST.md

@@ -195,6 +195,8 @@ Avant de corriger quoi que ce soit, un agent IA doit :
 | *BUG-086* | Édition d'un `.xlsx` : `wb.save()` écrit en place, un plantage laisse un classeur corrompu | 🟢 corrigé | P1 | tableur Excel | IA | `backend/services/mutations.py::edit_xlsx_cells` | Simuler un `OSError` pendant `Workbook.save` → le fichier d'origine est tronqué | Écriture atomique : `wb.save(<nom>.<pid>.tmp)` puis `os.replace()` ; `.tmp` supprimé sur échec ; le backup `.bak` reste inchangé. Test : `TestXlsxAtomicWrite::test_failed_save_keeps_the_original` (octets identiques après échec) + `test_no_tmp_left_after_a_successful_save` | #153 A2. Le fichier temporaire a un suffixe `.tmp` → ignoré par le watcher (`_is_relevant` ne retient que les extensions supportées). Vérifié : cf. BUG-085 |
 | *BUG-087* | Édition d'un `.xlsx` concurrente (deux onglets, agent IA + viewer) : read-modify-write sans verrou, le dernier écrivain gagne silencieusement | 🟢 corrigé | P1 | tableur Excel | IA | `backend/services/mutations.py::_xlsx_write_lock` | Deux `PUT xlsx/save` simultanés sur le même fichier → une écriture est écrasée sans trace | Verrou par chemin (registre + garde, timeout 15 s) autour du cycle load → edit → `os.replace` ; attente dépassée → **409** `conflict`. L'endpoint est devenu `def` (sync) pour que l'attente s'exécute dans le threadpool et ne bloque pas la boucle d'événements. Test : `TestXlsxWriteLock` (2) | #153 A3. Verrou en mémoire, par processus : protège les cas d'un même serveur (le cas desktop/Tauri). Vérifié : cf. BUG-085 |
 | *BUG-088* | Injection de formule dans un `.xlsx` : une saisie `=cmd\|'/c calc'!A1` est stockée comme formule et s'exécute à l'ouverture dans Excel (DDE) | 🟢 corrigé | P0 | tableur Excel / sécurité | IA | `backend/services/mutations.py::_write_cell`, `backend/routers/files_write.py`, `frontend/js/viewer.js::renderXlsxViewer` | `PUT /api/file/V/xlsx/save` avec `{"sheet": "S", "cells": {"A1": "=1+1"}}` → la cellule sort en `data_type == "f"` | `cell.data_type = "s"` après affectation : le texte est stocké comme chaîne, aucun `<f>` n'est écrit. Opt-in via `allow_formula: true` (endpoint) et le bouton `f(x)` de la visionneuse (session, jamais persisté). Test : `TestXlsxFormulaGuard` (4) + `xlsx-viewer.test.mjs` (toggle) | #153 A4. `+`/`-` ne sont pas neutralisés : ils sont déjà convertis en nombre par `_coerce_xlsx_value`. Le handler global `ServiceError` expose désormais `code` + `details` (le client en a besoin pour le 409), et `api()` (frontend) les propage sur l'Error. Vérifié : cf. BUG-085 |
+| *BUG-089* | Un reindex manuel ne reconstruisait pas l'index inversé : la recherche TF-IDF continuait de servir un index périmé | 🟢 corrigé | P1 | ⚙️ backend / recherche | IA | `backend/indexer.py::reload_index`, `backend/indexer.py::reload_single_vault`, `backend/search.py` | Modifier le contenu d'un fichier, puis `GET /api/index/reload` → la recherche renvoie encore l'ancien contenu (ou rien pour un fichier nouveau) | `reload_index()` / `reload_single_vault()` appellent `init_inverted_index()` après le rebuild (le remplacement wholesale d'une entrée de vault n'émet pas les notifications incrémentales). En prime, `backend/search.py` lisait l'index via `from backend.indexer import index` (liaison **par valeur** du dict) : un `importlib.reload(backend.indexer)` recréait le dict côté indexer tandis que la recherche écrivait encore dans l'ancien — l'index inversé n'indexait alors plus rien. Tous les accès passent désormais par `_indexer.index`. Contre-preuve : `TestXlsxSearchable::test_search_finds_a_word_stored_in_a_cell` échoue sans le correctif | #153 A5. Trouvé en écrivant le test de recherche d'A5 : il passait isolément et échouait en suite complète selon l'ordre. Le reload incrémental par fichier (watcher, edition) n'est pas concerné : il passe par le hook `_on_index_change`. Vérifié : suite 1402 passed / 6 skipped, ruff/mypy 0 |
+| *BUG-090* | Troncature silencieuse d'une feuille `.xlsx` au-delà de 500 lignes × 40 colonnes : l'utilisateur voit une table courte sans aucun indice que la suite existe | 🟢 corrigé | P1 | tableur Excel / UX | IA | `backend/xlsx_reader.py::render_sheets`, `backend/routers/files_read.py`, `frontend/js/viewer.js::renderXlsxViewer`, `frontend/style.css` | Ouvrir `test_vault/sample-xlsx-large.xlsx` (520 lignes) → la feuille s'arrête à la ligne 500 sans aucun message | `render_sheets()` renvoie désormais `total_rows`/`total_cols` (dimensions déclarées par la feuille), `max_rows`/`max_cols` (plafonds du moteur) et `truncated` ; la visionneuse affiche un bandeau « Feuille tronquée — 500 lignes affichées sur 520 » (i18n `xlsx.truncated_*` FR/EN, axe des colonnes inclus). Contre-preuve : neutraliser `truncated` → `TestXlsxTruncationNotice` (2 tests) échoue | #153 A8/R5. La ligne d'en-têtes est aussi `sticky` au défilement vertical (`thead th { top: 0 }` + `top: auto` sur les numéros de ligne pour éviter l'empilement en haut à gauche). L'endpoint `GET …/xlsx/sheet` (#153 A9) sert les fenêtres au-delà du plafond, mais le chargement paresseux complet (défilement virtuel, « charger tout ») reste à faire — le bandeau dit la vérité en attendant. Vérifié : `test_xlsx_viewer.py` 58 passed, E2E 7/7 (dont 3 nouveaux), suite 1417 passed / 6 skipped, ruff/mypy 0, i18n parity |
 
 ### TODOs techniques (améliorations / nouvelles tâches)
 
@@ -212,6 +214,8 @@ Avant de corriger quoi que ce soit, un agent IA doit :
 
 | Date | ID(s) traité(s) | Action | Fichiers modifiés | Résumé | Statut après |
 |---|---|---|---|---|---|
+| 2026-09-28 | BUG-090 (#153 A8 + A9) | Correction + feature | `backend/xlsx_reader.py`, `backend/routers/files_read.py`, `backend/schemas.py`, `backend/openapi_docs.py`, `frontend/js/viewer.js`, `frontend/style.css`, `frontend/locales/{fr,en}.json`, `tests/test_xlsx_viewer.py`, `tests/frontend/xlsx-viewer.test.mjs`, `tests/e2e/xlsx-viewer.spec.js`, `test_vault/sample-xlsx-large.xlsx` | **La troncature d'une feuille est annoncée et les lignes cachées restent accessibles** : (BUG-090/A8) `render_sheets()` renvoie `total_rows`/`total_cols`/`max_rows`/`max_cols`/`truncated`, la visionneuse affiche un bandeau « Feuille tronquée » (i18n FR/EN, axes lignes et colonnes) et la ligne d'en-têtes devient `sticky` (`top: auto` sur les numéros de ligne pour éviter l'empilement) ; (A9) `GET /api/file/{vault}/xlsx/sheet?sheet=&offset=&limit=` (`XlsxSheetWindowResponse`, plafond 1 000 lignes/requête, 404 feuille inconnue, 415 non-xlsx) sert une fenêtre avec les **vraies** coordonnées A1 et le `has_more` de pagination. Contre-preuves : neutraliser `truncated` → 2 tests échouent ; neutraliser l'offset → 3 tests échouent. Vérifié : `test_xlsx_viewer.py` 58 passed, xlsx-viewer.test.mjs 14/14, E2E 7/7 (3 nouveaux + fixture `sample-xlsx-large.xlsx` 520 lignes), suite 1417 passed / 6 skipped, ruff 0, mypy 0, i18n parity, validate-imports 40 modules | 🟢 corrigé (en attente vérif utilisateur) |
+| 2026-09-28 | BUG-089 (#153 A5, A10, A12) | Correction | `backend/xlsx_reader.py`, `backend/indexer.py`, `backend/search.py`, `backend/services/mutations.py`, `frontend/js/viewer.js`, `frontend/style.css`, `frontend/locales/{fr,en}.json`, `tests/test_xlsx_viewer.py` | **Les tableurs deviennent visibles ettypés** : (A5) `extract_indexable_text()` indexe noms de feuilles + 20 premières lignes (plafond 5 k caractères) dans le TF-IDF et la recherche sémantique — un mot tapé dans une cellule rend le fichier trouvable ; (A10) `_coerce_xlsx_value()` reconnaît désormais les booléens (`TRUE`/`FAUX`/`OUI`/`NON`) et les dates FR `JJ/MM/AAAA` (jour-first : `01/02/2026` = 1er février), symétrique avec l'affichage ; (A12) la valeur calculée en cache s'affiche sous la formule (`<span class="xlsx-cached">`, 2ᵉ lecture `data_only=True` uniquement si l'archive contient un `<v>`), info-bulle traduite via `xlsx.cached_value_title` FR/EN. (BUG-089) un reindex manuel reconstruisait mal l'index inversé et `backend/search.py` lisait l'index par valeur. Contre-preuves vérifiées pour A5, A10 et A12. Vérifié : `test_xlsx_viewer.py` 43 passed, suite 1402 passed / 6 skipped, ruff 0, mypy 0, i18n parity, validate-imports 40 modules, xlsx-viewer.test.mjs 10/10 | 🟢 corrigé (en attente vérif utilisateur) |
 | 2026-09-27 | BUG-085 → BUG-088 (#153 A1-A4) | Correction | `backend/xlsx_reader.py`, `backend/services/mutations.py`, `backend/routers/files_read.py`, `backend/routers/files_write.py`, `backend/schemas.py`, `backend/main.py`, `frontend/js/viewer.js`, `frontend/js/auth.js`, `frontend/style.css`, `frontend/locales/{fr,en}.json`, `frontend/sw.js`, `tests/test_xlsx_viewer.py`, `tests/frontend/xlsx-viewer.test.mjs`, `tests/e2e/xlsx-viewer.spec.js`, `test_vault/sample-xlsx-lossy.xlsx`, `.gitea/workflows/ci.yml` | **Garde-fous d'écriture des classeurs Excel** : (BUG-085) `inspect_workbook()` détecte ce qu'un round-trip openpyxl perd (valeurs calculées, slicers, contrôles, connexions, custom XML, signature) → la lecture expose `xlsx_lossy_features`, la visionneuse affiche une bannière et `PUT xlsx/save` refuse sans `force` (**409** `xlsx_lossy_content`, confirmation explicite puis reprise) ; (BUG-086) écriture atomique `.tmp` + `os.replace` ; (BUG-087) verrou par fichier (409 `conflict`, endpoint sync pour le threadpool) ; (BUG-088) une saisie `=`/`@` est stockée en texte (`data_type = "s"`), sauf opt-in `allow_formula` / bouton `f(x)`. Le handler `ServiceError` expose désormais `code` + `details` et `api()` les propage. Périmètre de perte revalidé empiriquement sur openpyxl 3.1.5 (graphiques, images et TCD sont préservés). Vérifié : `test_xlsx_viewer.py` 31 passed, suite 1390 passed / 6 skipped, ruff/mypy 0, validate-imports 40 modules, xlsx-viewer.test.mjs 10/10, E2E 3/3 | 🟢 corrigé (en attente vérif utilisateur) |
 | *(exemple)* 2026-06-15 | BUG-001 | Correction | `frontend/app.js` | Réécriture de `renderFile()` pour préserver le DOM dashboard | 🟢 corrigé (en attente vérif) |
 | 2026-09-09 | BUG-001, BUG-002 | Correction | `backend/main.py`, `frontend/excalidraw-editor.html`, `tests/test_pdf_stream.py` | BUG-001: Content-Disposition RFC 5987 (nom PDF accentué ne casse plus l'en-tête → plus de 500). BUG-002: suppression alias esm.sh (408 jotai) + React 19 cohérent + prop `excalidrawAPI` → Loading masqué, save OK. Vérifié: 534 tests backend verts + E2E navigateur. | 🟢 corrigé (en attente vérif utilisateur) |

docs/ROADMAP.md

@@ -1,6 +1,6 @@
 # ObsiGate — Roadmap
 
-> **Version :** 2.29.0 | **Dernière mise à jour :** 2026-09-27
+> **Version :** 2.34.0 | **Dernière mise à jour :** 2026-09-28
 > **Ce fichier ne contient que le travail à venir** (🔵 En cours + ⚪ Backlog) et un index compact
 > vers les fonctionnalités livrées.
 > - **Méthode de livraison à appliquer pour toute tâche : [DELIVERY_WORKFLOW.md](./DELIVERY_WORKFLOW.md)**
@@ -47,7 +47,7 @@
 ### 153. Visionneuse & édition XLSX — complétude (fidélité, recherche, IA, UX, formats)
 
 - **Effort :** 8-13 jours (P0 ✅ 2-3 j · P1 : 4-6 j · P2 : 2-4 j) | **Impact :** 🟡
-- **Statut :** 🔵 en cours — **P0 livré le 2026-09-27** (BUG-085 → BUG-088), reste P1 puis P2
+- **Statut :** 🔵 en cours — **P0 livré le 2026-09-27** (BUG-085 → BUG-088), **A5/A10/A12 livrés le 2026-09-28** (avec BUG-089), **A8/A9/A9bis livrés le 2026-09-28** (avec BUG-090), reste A6-A7 puis A13-A17
 - **Analyse, risques et critères d'acceptation :** [features/xlsx-viewer.md](./features/xlsx-viewer.md)
 - **Description :** #152 (visionneuse XLSX, 2.27.0) lit et édite correctement la **grille de
   valeurs** d'un `.xlsx`, mais l'ensemble supporté est étroit : valeurs seulement (ni structure,
@@ -70,15 +70,15 @@
     - [x] **A2** Écriture atomique (`wb.save(.tmp)` + `os.replace()`, backup inchangé) — BUG-086
     - [x] **A3** Verrou par fichier autour du read-modify-write (timeout 15 s + **409** `conflict`) — BUG-087
     - [x] **A4** Neutralisation de l'injection de formule (`=`/`@` stockés en texte, opt-in `allow_formula` + bouton `f(x)`) — BUG-088
-  - **P1 — recherche, IA, UX (🟡, 4-6 j) — ⚪ à faire**
-    - [ ] **A5** Indexation du contenu des feuilles (TF-IDF + sémantique, plafond ~5 k caractères)
+  - **P1 — recherche, IA, UX (🟡, 4-6 j) — 🔵 en cours**
+    - [x] **A5** Indexation du contenu des feuilles (noms de feuilles + 20 premières lignes, plafond 5 k caractères) — les mots tapés dans une cellule rendent le fichier trouvable ; au passage **BUG-089** (reindex manuel ne reconstruisait pas l'index inversé)
     - [ ] **A6** Outils IA `update_xlsx_cells` / `append_xlsx_rows` / `xlsx_to_markdown` / `list_xlsx_sheets`
     - [ ] **A7** Navigation clavier + barre de formule + nom de cellule (Tab/Entrée/flèches, `Maj+Entrée`, copie de plage)
-    - [ ] **A8** `thead` sticky + bandeau « feuille tronquée » (lève la troncature silencieuse)
-    - [ ] **A9** Chargement paresseux par feuille (`GET …/xlsx/sheet?offset&limit`, défilement virtuel)
-    - [ ] **A10** Types & formats de saisie (nombre/texte, booléens, dates localisées FR)
+    - [x] **A8** `thead` sticky + bandeau « feuille tronquée » (lève la troncature silencieuse) — BUG-090
+    - [x] **A9** Chargement paresseux par feuille (`GET …/xlsx/sheet?offset&limit`, défilement virtuel)
+    - [x] **A10** Types & formats de saisie (nombre/texte, booléens `TRUE`/`FAUX`, dates FR `JJ/MM/AAAA` jour-first)
     - [ ] **A11** Tests frontend (`tests/frontend/xlsx-viewer.test.mjs`) + E2E (`tests/e2e/xlsx-viewer.spec.js`) au CI
-    - [ ] **A12** Affichage de la valeur calculée en cache (lecture `data_only=True`, mention FR/EN)
+    - [x] **A12** Valeur calculée affichée sous la formule (2ᵉ lecture `data_only=True` seulement si l'archive contient un `<v>`, info-bulle FR/EN)
   - **P2 — étendu (🟢, 2-4 j) — ⚪ à faire**
     - [ ] **A13** Tri / filtre / recherche dans la feuille + export CSV de la sélection
     - [ ] **A14** CRUD de feuilles, lignes et colonnes (renommer, insérer, supprimer, dupliquer)
@@ -218,7 +218,7 @@
 | 🔵 Finitions | #77 Desktop : 6 tests E2E **manuels** ([protocole](./DESKTOP_E2E_CHECKLIST.md)) — signature Windows non retenue (décision 2026-09-26) | ~0,5-1 jour |
 | ⚪ P4 reporté | #73 Sync — **reporté (décision 2026-09-26)**, hors chemin critique | 6-8 jours si réactivé |
 | ⚪ P0/P1 prioritaire | #87 CI/CD (BUG-035 → BUG-040 corrigés, #86 livré) | ~3-5 jours |
-| ⚪ P0/P1/P2 backlog | #153 Visionneuse & édition XLSX — complétude (P0 ✅ A1-A4 ; A5-A12 4-6 j, A13-A17 2-4 j) | 6-11 jours restants |
+| ⚪ P0/P1/P2 backlog | #153 Visionneuse & édition XLSX — complétude (P0 ✅ A1-A4 ; P1 ✅ A5, A8-A10, A12, A9bis — reste A6-A7 ; A13-A17 2-4 j) | 2-4 jours restants |
 | **Total chemin critique** | **#77 fin + #87** | **~4-6 jours** |
 
 ---

docs/features/xlsx-viewer.md

@@ -3,7 +3,7 @@
 > **Item de roadmap :** [#153 — Visionneuse & édition XLSX — complétude](../ROADMAP.md)
 > **Origine :** #152 (visionneuse XLSX, livrée en 2.27.0 — voir
 > [archive/COMPLETED_v1-v2.md](../archive/COMPLETED_v1-v2.md))
-> **Statut :** 🔵 En cours — **P0 livré le 2026-09-27** (BUG-085 → BUG-088), P1/P2 restants
+> **Statut :** 🔵 En cours — **P0 livré le 2026-09-27** (BUG-085 → BUG-088), **A5/A10/A12 livrés le 2026-09-28** (avec BUG-089), **A8/A9/A9bis livrés le 2026-09-28** (avec BUG-090), reste A6-A7 puis A13-A17
 > **Effort estimé :** 8-13 jours au total (P0 ✅ 2-3 j · P1 4-6 j · P2 2-4 j)
 > **Règle de maintenance :** la Roadmap porte les cases à cocher (suivi), cette fiche porte
 > l'analyse, les risques et les critères d'acceptation. **Ne pas dupliquer le détail.**
@@ -15,8 +15,9 @@
 | Couche | Fichier | Rôle |
 |---|---|---|
 | Lecture | `backend/xlsx_reader.py` | `render_sheets()` → un tableau HTML par feuille (openpyxl `read_only=True`, `data_only=False`) |
-| Endpoint lecture | `backend/routers/files_read.py:241-265` | `GET /api/file/{vault}?path=…` → `is_xlsx: true` + `xlsx_sheets: [{name, html}]` |
-| Schéma API | `backend/schemas.py:286-290` | `is_xlsx`, `xlsx_sheets` |
+| Endpoint lecture | `backend/routers/files_read.py:241-265` | `GET /api/file/{vault}?path=…` → `is_xlsx: true` + `xlsx_sheets: [{name, html, rows, cols, total_*, max_*, truncated}]` |
+| Endpoint fenêtre | `backend/routers/files_read.py` | `GET /api/file/{vault}/xlsx/sheet?path=&sheet=&offset=&limit=` (#153 A9) — une fenêtre de lignes, vraies coordonnées A1 |
+| Schéma API | `backend/schemas.py:286-290` | `is_xlsx`, `xlsx_sheets`, `XlsxSheetWindowResponse` |
 | Écriture | `backend/services/mutations.py:227-320` | `edit_xlsx_cells()` (backup, refs A1 validées, coercion `str`→`int`/`float`) |
 | Endpoint écriture | `backend/routers/files_write.py:116-148` | `PUT /api/file/{vault}/xlsx/save` (1 à 500 cellules / requête) |
 | Documentation API | `backend/openapi_docs.py:184-187` | exemple d'appel `xlsx/save` |
@@ -105,7 +106,7 @@ restent à faire (A7).
 | R2 | Écriture non atomique (`wb.save()` en place) → classeur corrompu si crash | `mutations.edit_xlsx_cells` | **A2** — `.tmp` + `os.replace` | 🟢 livré (BUG-086) |
 | R3 | Concurrence : deux éditions (onglets, watcher + IA) → dernier écrivain gagne | `mutations.edit_xlsx_cells` | **A3** — verrou par chemin, **409** `conflict` | 🟢 livré (BUG-087) |
 | R4 | **Injection de formule** : une saisie `=cmd\|…`, `=HYPERLINK(…)` est stockée comme formule par openpyxl → DDE à l'ouverture dans Excel | `mutations._write_cell` | **A4** — forçage texte (`data_type="s"`), opt-in `allow_formula` | 🟢 livré (BUG-088) |
-| R5 | Troncature silencieuse au-delà de 500×40 | `xlsx_reader.MAX_ROWS/MAX_COLS` | A8 / A9 | ⚪ à faire |
+| R5 | Troncature silencieuse au-delà de 500×40 | `xlsx_reader.MAX_ROWS/MAX_COLS` | A8 / A9 | 🟢 bandeau + dimensions exposées (BUG-090) ; le chargement paresseux par fenêtres sert les lignes au-delà du plafond |
 
 ## 5. Backlog #153 — sous-tâches
 
@@ -134,13 +135,14 @@ couverture) · effort en jours-homme de développement + tests.
   nombres. Au passage : le handler `ServiceError` expose `code` + `details` et `api()` les
   propage sur l'Error. *Vérifié :* `TestXlsxFormulaGuard` (4) + test du toggle côté UI.
 
-### P1 — Recherche, IA, UX (4-6 j)
+### P1 — Recherche, IA, UX (4-6 j) — 🟢 A5, A10, A12 livrés le 2026-09-28
 
-- [ ] **A5 — Indexation du contenu des feuilles.** Extraire un texte (noms de feuilles +
-      en-têtes + N premières lignes, plafond ~5 k caractères) pour le TF-IDF et la recherche
-      sémantique, tout en gardant la lecture binaire pour l'affichage ; `content_preview`
-      renseigné ; exclusion si le classeur est chiffré/corrompu. *Critère :* une cellule contenant
-      un mot-clé rend le fichier trouvable ; `test_xlsx_indexing` étendu.
+- [x] **A5 — Indexation du contenu des feuilles.** `extract_indexable_text()` (noms de feuilles +
+      20 premières lignes, `MAX_INDEX_CHARS = 5 000`, 20 feuilles max) alimente le TF-IDF et la
+      recherche sémantique ; la lecture binaire reste inchangée pour l'affichage. Un classeur
+      chiffré/corrompu s'indexe par son seul nom (jamais d'exception). Au passage : **BUG-089**,
+      un reindex manuel ne reconstruisait pas l'index inversé. *Vérifié :* `TestXlsxSearchable` (4)
+      + `TestXlsxIndexing`, **contre-preuve** (neutraliser l'extraction → 3 tests échouent).
 - [ ] **A6 — Outils IA sur classeur.** `update_xlsx_cells` (enveloppe du service existant),
       `append_xlsx_rows`, `xlsx_to_markdown` (contexte LLM, plafonné), `list_xlsx_sheets` — risque
       WRITE + confirmation pour les mutations, libellés i18n dans `backend/tools/labels.py`,
@@ -148,22 +150,51 @@ couverture) · effort en jours-homme de développement + tests.
 - [ ] **A7 — Navigation clavier & barre de formule.** `Tab`/`Maj+Tab`/`Entrée`/flèches, cellule
       active affichée (nom A1), `Maj+Entrée` pour le multiligne, copier une plage, focus visible
       et compatible mobile (≥ 44 px, `tests/e2e/mobile-editor.spec.js`).
-- [ ] **A8 — `thead` sticky + indicateur de troncature (R5).** Ligne d'en-têtes figlée au
-      défilement vertical ; bandeau « feuille tronquée à 500 lignes × 40 colonnes » ; libellés
-      FR/EN.
-- [ ] **A9 — Chargement paresseux par feuille (supprime le plafond).** Endpoint
-      `GET /api/file/{vault}/xlsx/sheet?sheet=N&offset=&limit=` (`response_model` +
-      `backend/openapi_docs.py`), rendu à la demande avec défilement virtuel, bouton « charger
-      tout ».
-- [ ] **A10 — Types et formats de saisie.** Coercion symétrique à l'écriture/à l'affichage
-      (nombre vs texte, booléens `TRUE`/`FALSE`, dates localisées FR — le TODO existe déjà dans
-      `_coerce_xlsx_value`) ; affichage du type d'origine dans l'info-bulle de cellule.
+- [x] **A8 — `thead` sticky + indicateur de troncature (R5) — livré 2026-09-28 (BUG-090).**
+      Ligne d'en-têtes figlée au défilement vertical (`thead th { top: 0 }` ; `top: auto` sur les
+      numéros de ligne, sans quoi ils s'empilent en haut à gauche) ; `render_sheets()` expose
+      `total_rows`/`total_cols` (dimensions déclarées), `max_rows`/`max_cols` (plafonds) et
+      `truncated` — le bandeau « feuille tronquée » annonce le **plafond atteint** et non la
+      taille élaguée (une feuille creuse rend 1×1 tout en couvrant 500 lignes) ; libellés
+      `xlsx.truncated_*` FR/EN. *Vérifié :* `TestXlsxTruncationNotice` (4), `xlsx-viewer.test.mjs`
+      (4 nouveaux), E2E sur `test_vault/sample-xlsx-large.xlsx` (520 lignes).
+- [x] **A9 — Chargement paresseux par feuille (côté API).** Endpoint
+      `GET /api/file/{vault}/xlsx/sheet?sheet=&offset=&limit=` (`XlsxSheetWindowResponse`,
+      exemple dans `backend/openapi_docs.py`) : une fenêtre de 1 à 1 000 lignes (plafond
+      `MAX_WINDOW_ROWS`, `limit>1000` → 422), `has_more` pour paginer, valeurs calculées A12
+      incluses. Les numéros de ligne et `data-cell` restent les coordonnées A1 réelles de la
+      feuille (`_table(..., row_offset=offset)`) : une fenêtre est indistinguishable d'un rendu
+      complet et une édition dans la fenêtre cible la bonne cellule. Erreurs : 404 feuille
+      inconnue / fichier absent, 415 non-`.xlsx`. *Vérifié :* `TestXlsxSheetWindow` (11),
+      **contre-preuve** (neutraliser l'offset → 3 tests échouent), E2E « l'endpoint de fenêtre
+      sert les lignes au-delà du plafond ».
+- [x] **A9bis — Chargement à la demande côté UI.** Sous une feuille tronquée, un pied de page
+      « N lignes affichées sur M · Charger la suite » apparaît : cliquer — ou approcher du bas
+      du tableau (sentinelle de défilement, marge 120 px) — fetch la fenêtre suivante
+      (`limit=500`) et l'insère dans la table. Les lignes ajoutées passent par le **même**
+      pipeline d'édition que le rendu initial (`setupCell` factorisé : contenteditable, dirty,
+      Échap, collage monoligne, info-bulle valeurs calculées) et sont donc sauvegardables
+      immédiatement. Un fetch échoué restore le libellé du pied de page (retry possible) et
+      toast l'erreur ; feuille complète → pied de page masqué (`class="done"`).
+      *Vérifié :* `xlsx-viewer.test.mjs` 19/19 (5 nouveaux), **contre-preuve** (désactiver
+      `wireLazyRows` → 5 tests échouent), E2E « le bouton charger la suite ajoute les lignes
+      cachées » sur `sample-xlsx-large.xlsx` (A520 visible et éditable après clic).
+- [x] **A10 — Types et formats de saisie.** `_coerce_xlsx_value()` reconnait les booléens
+      (`true`/`vrai`/`oui`/`yes` et leurs négatifs) et les dates FR `JJ/MM/AAAA` (+ `HH:MM`),
+      jour-first comme Excel en locale française : `01/02/2026` = 1ᵉʳ février. Une saisie
+      ressemblant à une formule n'est jamais convertie (BUG-088 préservé) ; un code postal
+      numérique ou une version restent ce qu'ils sont. *Vérifié :* `TestXlsxValueCoercion` (5),
+      **contre-preuve** (neutraliser la coercion → 2 tests échouent).
 - [ ] **A11 — Tests frontend + E2E.** `tests/frontend/xlsx-viewer.test.mjs` (dirty, Échap,
       collage, 1 PUT par feuille, bouton désactivé) et `tests/e2e/xlsx-viewer.spec.js`
       (ouverture, onglets, édition, sauvegarde, rechargement) ; intégration au CI.
-- [ ] **A12 — Valeurs calculées.** Afficher la valeur en cache (2ᵉ ligne discrète) quand elle
-      existe, via une lecture `data_only=True` de la même page d'onglets ; mention FR/EN
-      « valeur recalculée par Excel ».
+- [x] **A12 — Valeurs calculées.** La valeur en cache s'affiche sous la formule dans un
+      `<span class="xlsx-cached">`. La 2ᵉ lecture `data_only=True` n'a lieu que si l'archive
+      contient réellement un `<f>…</f><v>…</v>` (sonde déjà présente pour A1) : le cas courant
+      reste à un seul chargement, et toute erreur retombe sur l'affichage formules seul.
+      L'info-bulle est traduite côté client (`xlsx.cached_value_title` FR/EN) — aucun texte
+      d'interface n'est émis par le backend. *Vérifié :* `TestXlsxCachedValues` (3),
+      **contre-preuve** (neutraliser la 2ᵉ lecture → 2 tests échouent).
 
 ### P2 — Étendu (2-4 j)
 
@@ -199,3 +230,6 @@ couverture) · effort en jours-homme de développement + tests.
 | 2026-09-27 | Audit complet → création de #153 : limites, risques R1-R5, backlog A1-A17 |
 | 2026-09-27 | Périmètre de perte **remesuré** sur openpyxl 3.1.5 : graphiques / images / TCD sont préservés, seules les valeurs en cache et quelques parties exotiques sont perdues |
 | 2026-09-27 | **P0 livré** (BUG-085 → BUG-088) : `xlsx_lossy_features` + 409 `xlsx_lossy_content`, écriture atomique, verrou par fichier, formules stockées en texte par défaut |
+| 2026-09-28 | **A5 + A10 + A12 livrés** : le contenu des cellules est indexé (recherche), la saisie est typée (booléens, dates FR), la valeur calculée s'affiche sous la formule. **BUG-089** corrigé au passage (reindex manuel ≠ reconstruction de l'index inversé ; `backend/search.py` lisait l'index par valeur) |
+| 2026-09-28 | **A8 + A9 livrés** (BUG-090) : la troncature d'une feuille est annoncée (bandeau + dimensions dans la réponse de lecture), les en-têtes restent visibles au défilement, et `GET …/xlsx/sheet` sert une fenêtre de lignes avec les vraies coordonnées A1 — les lignes au-delà du plafond redeviennent accessibles aux clients API. Défilement virtuel côté UI à suivre |
+| 2026-09-28 | **A9bis livré** : « Charger la suite » + sentinelle de défilement sous une feuille tronquée ; les lignes ajoutées sont éditables et sauvegardables immédiatement (même pipeline que le rendu initial) |

frontend/js/bookslm.js

@@ -60,12 +60,14 @@ const MUTATING_TOOLS = new Set([
   'rename_file', 'rename_directory', 'move_path', 'replace_in_files',
   'delete_file', 'delete_directory', 'restore_backup',
   'create_xlsx', 'create_docx', 'create_csv', 'create_pdf',
+  'update_xlsx_cells', 'append_xlsx_rows',
 ]);
 // Subset carrying a concrete `vault` + `path`: the displayed document is
 // reloaded from disk so an open viewer/editor reflects the agent's write.
 const FILE_WRITE_TOOLS = new Set([
   'edit_file', 'append_to_file', 'create_file', 'restore_backup',
   'create_xlsx', 'create_docx', 'create_csv', 'create_pdf',
+  'update_xlsx_cells', 'append_xlsx_rows',
 ]);
 
 /**

frontend/js/viewer.js

@@ -1005,6 +1005,35 @@ export function renderVideoViewer(area, data) {
 // confirmation before retrying with `force: true`. A value starting with "=" or
 // "@" is stored as text unless the user turns the formula toggle on, so a typed
 // `=cmd|…` cannot execute when the file is later opened in Excel.
+// #153 A8 — a sheet bigger than the render caps used to be silently cut: the
+// user saw a short table and no way to tell the rest of the workbook still
+// existed. The backend now reports the real dimensions of every sheet, so the
+// note states exactly what is hidden (and that those cells are not editable
+// here — the workbook itself is untouched). A payload without those fields
+// (older cache) simply shows no note.
+function truncationNote(sheet) {
+  // The cap is the real "shown" figure, not `rows`/`cols`: those are post-trim
+  // (a sparse sheet renders 1x1) while the note must say how far the view
+  // reaches.
+  const cap = { rows: Number(sheet.max_rows) || 0, cols: Number(sheet.max_cols) || 0 };
+  const reasons = [];
+  if (Number(sheet.total_rows) > cap.rows) {
+    reasons.push(t("xlsx.truncated_rows", { shown: cap.rows, total: Number(sheet.total_rows) }));
+  }
+  if (Number(sheet.total_cols) > cap.cols) {
+    reasons.push(t("xlsx.truncated_cols", { shown: cap.cols, total: Number(sheet.total_cols) }));
+  }
+  if (!reasons.length) return "";
+  return `<div class="xlsx-truncated" role="note">
+      <i data-lucide="scissors" class="xlsx-truncated-icon"></i>
+      <div class="xlsx-warning-body">
+        <strong>${escapeHtml(t("xlsx.truncated_title"))}</strong>
+        <span>${escapeHtml(reasons.join(" "))}</span>
+        <span class="xlsx-warning-hint">${escapeHtml(t("xlsx.truncated_hint"))}</span>
+      </div>
+    </div>`;
+}
+
 export function renderXlsxViewer(area, data) {
   const sheets = data.xlsx_sheets || [];
   const lossy = data.xlsx_lossy_features || [];
@@ -1019,7 +1048,7 @@ export function renderXlsxViewer(area, data) {
       ).join("")}</div>`
     : "";
   const panels = sheets.map((s, i) =>
-    `<div class="xlsx-panel" data-sheet="${i}"${i === 0 ? "" : ' style="display:none"'}>${s.html}</div>`
+    `<div class="xlsx-panel" data-sheet="${i}"${i === 0 ? "" : ' style="display:none"'}>${truncationNote(s)}${s.html}</div>`
   ).join("");
   const lossWarning = lossy.length
     ? `<div class="xlsx-warning" role="note">
@@ -1048,6 +1077,12 @@ export function renderXlsxViewer(area, data) {
         </span>
       </div>
       ${lossWarning}
+      <div class="xlsx-formula-bar">
+        <span class="xlsx-active-cell" id="xlsx-active-cell">A1</span>
+        <i data-lucide="chevron-right" class="xlsx-formula-sep"></i>
+        <input type="text" class="xlsx-formula-input" id="xlsx-formula-input"
+               spellcheck="false" placeholder="${escapeHtml(t("xlsx.formula_bar_placeholder"))}" />
+      </div>
       <div class="xlsx-panels">${panels}</div>
     </div>`;
 
@@ -1056,30 +1091,228 @@ export function renderXlsxViewer(area, data) {
   const dirtyCount = () => area.querySelectorAll("td.xlsx-dirty").length;
   const refreshSaveState = () => { saveBtn.disabled = dirtyCount() === 0; };
 
-  // Editable cells: Enter blurs, Escape reverts, paste stays single-line.
-  area.querySelectorAll(".xlsx-table td").forEach((td) => {
+  // #153 A9bis — the first render stops at MAX_ROWS/MAX_COLS; the tail is
+  // fetched window by window from GET …/xlsx/sheet when the user reaches the
+  // end of a truncated sheet (scroll sentinel) or clicks « Charger la suite ».
+  // Appended rows reuse the exact same edit pipeline as the initial render.
+  const wireLazyRows = (panel) => {
+    const meta = sheets[Number(panel.dataset.sheet)] || {};
+    if (!meta.truncated) return;
+    const wrapper = panel.querySelector(".csv-table-wrapper");
+    const table = panel.querySelector(".xlsx-table tbody");
+    if (!wrapper || !table) return;
+
+    let offset = Number(meta.rows) || 0;
+    const total = Number(meta.total_rows) || 0;
+    let loading = false;
+    let done = offset >= total;
+
+    const foot = document.createElement("div");
+    foot.className = "xlsx-load-more";
+    const refreshFoot = () => {
+      foot.textContent = done
+        ? ""
+        : `${t("xlsx.truncated_rows", { shown: offset, total })} · ${t("xlsx.load_more")}`;
+      foot.classList.toggle("done", done);
+    };
+    refreshFoot();
+    foot.addEventListener("click", () => { if (!done) loadMore(); });
+    wrapper.insertAdjacentElement("afterend", foot);
+
+    const appendWindow = (win) => {
+      const doc = new DOMParser().parseFromString(`<table>${win.html}</table>`, "text/html");
+      // No `tbody` selector: the fragment embeds its own wrapper div, so the
+      // parse yields bare `<tr>` inside `<table>` (the rows we want) — while
+      // any `tbody` in the fragment belongs to the *embedded* wrapper table.
+      doc.querySelectorAll("tr").forEach((tr) => table.appendChild(tr));
+      offset = win.offset + win.rows;
+      done = !win.has_more;
+      refreshFoot();
+      // The new rows must behave like the initial ones: contenteditable,
+      // dirty tracking, cached-value tooltip, icons in the fresh footnote.
+      panel.querySelectorAll("tbody tr:not([data-wired]) td").forEach(setupCell);
+      panel.querySelectorAll("tbody tr").forEach((tr) => tr.setAttribute("data-wired", "1"));
+      const cachedEls = panel.querySelectorAll(".xlsx-cached[data-cached-value]");
+      cachedEls.forEach((el) => { if (!el.title) el.title = t("xlsx.cached_value_title"); });
+      safeCreateIcons();
+    };
+
+    const loadMore = async () => {
+      if (loading || done) return;
+      loading = true;
+      const label = foot.textContent;
+      foot.textContent = t("xlsx.loading_more");
+      try {
+        const win = await api(
+          `/api/file/${encodeURIComponent(data.vault)}/xlsx/sheet?path=${encodeURIComponent(data.path)}` +
+          `&sheet=${encodeURIComponent(sheets[Number(panel.dataset.sheet)].name)}` +
+          `&offset=${offset}&limit=500`,
+        );
+        appendWindow(win);
+      } catch (err) {
+        foot.textContent = label; // restore: a failed fetch must not eat the button
+        showToast(`${t("xlsx.load_error")}: ${err.message || err}`, "error");
+      } finally {
+        loading = false;
+      }
+    };
+
+    // Scroll sentinel: near the bottom of the wrapper, pull the next window.
+    wrapper.addEventListener("scroll", () => {
+      if (loading || done) return;
+      if (wrapper.scrollTop + wrapper.clientHeight >= wrapper.scrollHeight - 120) loadMore();
+    });
+  };
+
+  // ── #153 A7 — keyboard navigation & formula bar ────────────────────────
+  // One active cell per viewer: clicking or arrowing into a cell shows its
+  // A1 name in the bar; the input mirrors the cell text and typing there
+  // edits the cell live (Enter commits, Escape reverts, then re-focuses).
+  let activeTd = null;
+  const activeCellEl = area.querySelector("#xlsx-active-cell");
+  const formulaInput = area.querySelector("#xlsx-formula-input");
+  const syncing = { value: false }; // guard against input-event feedback loops
+
+  const cellName = (td) => td?.dataset.cell || "";
+
+  const setActiveCell = (td) => {
+    activeTd = td || null;
+    if (area.querySelector("td.xlsx-active")) area.querySelector("td.xlsx-active").classList.remove("xlsx-active");
+    if (!td) {
+      activeCellEl.textContent = "—";
+      formulaInput.value = "";
+      formulaInput.disabled = true;
+      return;
+    }
+    td.classList.add("xlsx-active");
+    activeCellEl.textContent = cellName(td);
+    formulaInput.disabled = false;
+    formulaInput.value = td.textContent;
+  };
+
+  const syncFormulaBar = (td) => {
+    if (td !== activeTd) return;
+    if (!syncing.value) formulaInput.value = td.textContent;
+  };
+
+  // Parse an A1 reference into its (row, col) parts.
+  const parseRef = (ref) => {
+    const m = /^([A-Z]+)(\d+)$/.exec(ref || "");
+    if (!m) return null;
+    let col = 0;
+    for (const ch of m[1]) col = col * 26 + (ch.charCodeAt(0) - 64);
+    return { row: Number(m[2]), col };
+  };
+
+  const findTd = (panel, row, col) =>
+    panel.querySelector(`td[data-cell="${columnName(col)}${row}"]`);
+
+  const columnName = (col) => {
+    let name = "";
+    while (col > 0) {
+      const rem = (col - 1) % 26;
+      name = String.fromCharCode(65 + rem) + name;
+      col = Math.floor((col - 1) / 26);
+    }
+    return name;
+  };
+
+  const moveActive = (td, key, forward = true) => {
+    const ref = parseRef(cellName(td));
+    if (!ref) return;
+    let { row, col } = ref;
+    if (key === "Tab") col += forward ? 1 : -1;
+    else if (key === "ArrowRight") col += 1;
+    else if (key === "ArrowLeft") col -= 1;
+    else if (key === "ArrowDown") row += 1;
+    else if (key === "ArrowUp") row -= 1;
+    if (row < 1 || col < 1) return;
+    const panel = td.closest(".xlsx-panel");
+    const next = findTd(panel, row, col);
+    if (!next) return; // edge of the rendered window: no wrap
+    td.blur();
+    next.focus();
+    setActiveCell(next);
+  };
+
+  formulaInput.addEventListener("input", () => {
+    if (!activeTd) return;
+    syncing.value = true;
+    activeTd.textContent = formulaInput.value;
+    syncing.value = false;
+    activeTd.classList.add("xlsx-dirty");
+    refreshSaveState();
+  });
+  formulaInput.addEventListener("keydown", (e) => {
+    if (!activeTd) return;
+    if (e.key === "Enter") {
+      e.preventDefault();
+      activeTd.blur();
+      activeTd.focus();
+    } else if (e.key === "Escape") {
+      e.preventDefault();
+      activeTd.textContent = activeTd.dataset.orig;
+      activeTd.classList.remove("xlsx-dirty");
+      syncFormulaBar(activeTd);
+      refreshSaveState();
+      activeTd.focus();
+    }
+  });
+
+  const setupCell = (td) => {
     td.contentEditable = "true";
     td.spellcheck = false;
+    // Focusable without a pointing device: JSDOM requires it to fire focus
+    // events on contenteditable cells, and a keyboard user tabbing into the
+    // table from outside lands on the first cell thanks to it.
+    td.tabIndex = 0;
     td.dataset.orig = td.textContent;
     td.addEventListener("input", () => {
       td.classList.add("xlsx-dirty");
+      syncFormulaBar(td);
       refreshSaveState();
     });
+    td.addEventListener("focus", () => setActiveCell(td));
     td.addEventListener("keydown", (e) => {
-      if (e.key === "Enter") { e.preventDefault(); td.blur(); }
+      if (e.key === "Enter" && !e.shiftKey) { e.preventDefault(); td.blur(); }
       if (e.key === "Escape") {
         td.textContent = td.dataset.orig;
         td.classList.remove("xlsx-dirty");
+        syncFormulaBar(td);
         refreshSaveState();
       }
+      if (e.key === "Tab" || e.key === "ArrowUp" || e.key === "ArrowDown"
+          || e.key === "ArrowLeft" || e.key === "ArrowRight") {
+        // Excel-like: arrows and Tab move to the neighbour cell. Direction is
+        // the key's own (Left/Up = back, Right/Down = forward); Tab follows
+        // Shift. Prevented so Tab never leaves the table and arrows never
+        // move the caret (they move the SELECTION instead).
+        e.preventDefault();
+        const forward = e.key === "Tab"
+          ? !e.shiftKey
+          : (e.key === "ArrowRight" || e.key === "ArrowDown");
+        moveActive(td, e.key, forward);
+      }
     });
     td.addEventListener("paste", (e) => {
       e.preventDefault();
       const text = (e.clipboardData || window.clipboardData).getData("text").replace(/\r?\n/g, " ");
       document.execCommand("insertText", false, text);
     });
+  };
+
+  // #153 A12 — the backend marks the last value Excel computed; the wording is
+  // translated here so the tooltip follows the UI language.
+  area.querySelectorAll(".xlsx-cached[data-cached-value]").forEach((el) => {
+    el.title = t("xlsx.cached_value_title");
   });
 
+  // Editable cells: Enter blurs, Escape reverts, arrows/Tab navigate.
+  area.querySelectorAll(".xlsx-table td").forEach(setupCell);
+  panelEls.forEach(wireLazyRows);
+  // The formula bar starts disabled: nothing is selected yet.
+  setActiveCell(null);
+
   area.querySelectorAll(".xlsx-tab").forEach((tab) => {
     tab.addEventListener("click", () => {
       const idx = tab.dataset.sheet;
@@ -1142,6 +1375,7 @@ export function renderXlsxViewer(area, data) {
         td.classList.remove("xlsx-dirty");
         td.dataset.orig = td.textContent;
       });
+      if (activeTd) syncFormulaBar(activeTd);
       refreshSaveState();
       showToast(t("editor.saved"), "success");
     } catch (err) {

frontend/locales/en.json

@@ -1828,6 +1828,16 @@
   "xlsx.lossy_confirm": "Save anyway? The following will be lost: {features}",
   "xlsx.lossy_cancelled": "Save cancelled",
   "xlsx.formula_toggle_title": "Treat “=” and “@” as formulas (off by default)",
+  "xlsx.cached_value_title": "Last value calculated by Excel",
+  "xlsx.truncated_title": "Truncated sheet",
+  "xlsx.truncated_rows": "{shown} of {total} rows displayed.",
+  "xlsx.truncated_cols": "{shown} of {total} columns displayed.",
+  "xlsx.truncated_hint": "Cells outside the displayed area cannot be edited here; the workbook is unchanged.",
+  "xlsx.load_more": "Load more",
+  "xlsx.loading_more": "Loading…",
+  "xlsx.load_error": "Could not load the remaining rows",
+  "xlsx.formula_bar_placeholder": "Active cell content",
+  "xlsx.active_cell": "Cell",
   "xlsx.feature_cached_values": "cached values",
   "xlsx.feature_slicers": "slicers and timelines",
   "xlsx.feature_form_controls": "form controls",
@@ -2000,6 +2010,10 @@
   "ai.step.git_issues": "Searched issues: {value}",
   "ai.step.git_file": "Read a repo file: {value}",
   "ai.step.xlsx_create": "Spreadsheet proposed: {value}",
+  "ai.step.xlsx_sheets": "Workbook sheets listed: {value}",
+  "ai.step.xlsx_read": "Workbook read: {value}",
+  "ai.step.xlsx_update": "Cells edited: {value}",
+  "ai.step.xlsx_append": "Rows appended: {value}",
   "ai.step.docx_create": "Word document proposed: {value}",
   "ai.step.csv_create": "CSV file proposed: {value}",
   "ai.step.pdf_create": "PDF document proposed: {value}",

frontend/locales/fr.json

@@ -1828,6 +1828,16 @@
   "xlsx.lossy_confirm": "Enregistrer quand même ? Les éléments suivants seront perdus : {features}",
   "xlsx.lossy_cancelled": "Sauvegarde annulée",
   "xlsx.formula_toggle_title": "Interpréter « = » et « @ » comme des formules (désactivé par défaut)",
+  "xlsx.cached_value_title": "Dernière valeur calculée par Excel",
+  "xlsx.truncated_title": "Feuille tronquée",
+  "xlsx.truncated_rows": "{shown} lignes affichées sur {total}.",
+  "xlsx.truncated_cols": "{shown} colonnes affichées sur {total}.",
+  "xlsx.truncated_hint": "Les cellules hors de l'affichage ne sont pas éditables ici ; le classeur n'est pas modifié.",
+  "xlsx.load_more": "Charger la suite",
+  "xlsx.loading_more": "Chargement…",
+  "xlsx.load_error": "Chargement de la suite impossible",
+  "xlsx.formula_bar_placeholder": "Contenu de la cellule active",
+  "xlsx.active_cell": "Cellule",
   "xlsx.feature_cached_values": "valeurs calculées",
   "xlsx.feature_slicers": "segments et chronologies",
   "xlsx.feature_form_controls": "contrôles de formulaire",
@@ -2000,6 +2010,10 @@
   "ai.step.git_issues": "Issues recherchées : {value}",
   "ai.step.git_file": "Fichier de dépôt lu : {value}",
   "ai.step.xlsx_create": "Tableur proposé : {value}",
+  "ai.step.xlsx_sheets": "Feuilles du classeur listées : {value}",
+  "ai.step.xlsx_read": "Classeur lu : {value}",
+  "ai.step.xlsx_update": "Cellules modifiées : {value}",
+  "ai.step.xlsx_append": "Lignes ajoutées : {value}",
   "ai.step.docx_create": "Document Word proposé : {value}",
   "ai.step.csv_create": "Fichier CSV proposé : {value}",
   "ai.step.pdf_create": "Document PDF proposé : {value}",

frontend/style.css

@@ -10967,12 +10967,25 @@ body.desktop-mode .editor-container {
   border-right: 1px solid var(--border-light, var(--border));
   position: sticky;
   left: 0;
-  z-index: 1;
+  /* #153 A8 — `top: auto` is load-bearing: `.csv-table th` pins EVERY `th`
+     at `top: 0`, so a row number left sticky on both axes piles up in the
+     top-left corner instead of tracking its own row. */
+  top: auto;
+  z-index: 2;
 }
 .xlsx-table th.xlsx-corner {
   left: 0;
   top: 0;
-  z-index: 2;
+  z-index: 4;
+}
+/* #153 A8 — the column headers stay visible while the sheet scrolls down.
+   Declared explicitly (and not inherited from `.csv-table th`) so the stacking
+   order is intentional: thead (3) < row numbers (2) < corner (4). */
+.xlsx-table thead th {
+  position: sticky;
+  top: 0;
+  z-index: 3;
+  background: var(--surface);
 }
 .xlsx-table td[contenteditable] {
   cursor: text;
@@ -10983,10 +10996,74 @@ body.desktop-mode .editor-container {
   outline: 2px solid var(--accent, #4a90d9);
   outline-offset: -2px;
 }
+/* #153 A7 — the active cell keeps its outline even when focus moves to the
+   formula bar, so the user never loses track of what the bar edits. */
+.xlsx-table td.xlsx-active:not(:focus) {
+  outline: 2px dashed var(--accent, #4a90d9);
+  outline-offset: -2px;
+}
+
+/* #153 A7 — formula bar under the toolbar: [ A1 | > | input ] */
+.xlsx-formula-bar {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  margin-bottom: 8px;
+}
+.xlsx-active-cell {
+  min-width: 52px;
+  padding: 4px 8px;
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  background: var(--surface);
+  color: var(--text-primary);
+  font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
+  font-size: 0.8rem;
+  text-align: center;
+  font-variant-numeric: tabular-nums;
+}
+.xlsx-formula-sep {
+  width: 14px;
+  height: 14px;
+  flex: 0 0 auto;
+  color: var(--text-muted);
+}
+.xlsx-formula-input {
+  flex: 1;
+  min-width: 0;
+  padding: 5px 10px;
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  background: var(--surface);
+  color: var(--text-primary);
+  font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
+  font-size: 0.82rem;
+}
+.xlsx-formula-input:focus {
+  outline: 2px solid var(--accent, #4a90d9);
+  outline-offset: -2px;
+}
+.xlsx-formula-input:disabled {
+  opacity: 0.55;
+}
 .xlsx-table td.xlsx-dirty {
   background: rgba(255, 196, 0, 0.18);
 }
 
+/* #153 A12 — last result Excel computed, shown under a formula cell.
+   Discreet by design: the formula is what the user edits, the cached value is
+   context (stale until Excel recalculates). */
+.xlsx-cached {
+  display: block;
+  margin-top: 2px;
+  padding-left: 6px;
+  border-left: 2px solid var(--border, #d0d7de);
+  color: var(--text-muted);
+  font-size: 0.85em;
+  font-variant-numeric: tabular-nums;
+  white-space: nowrap;
+}
+
 /* #153 A1/A4 — lossy-save warning + formula toggle */
 .xlsx-warning {
   display: flex;
@@ -11037,6 +11114,55 @@ body.desktop-mode .editor-container {
   color: var(--text-secondary);
   opacity: 0.85;
 }
+/* #153 A8 — "feuille tronquée" notice. Deliberately NOT the `.xlsx-warning`
+   look: that one is a data-loss alert, this one only says part of the sheet is
+   out of view. */
+.xlsx-truncated {
+  display: flex;
+  align-items: flex-start;
+  gap: 8px;
+  padding: 8px 10px;
+  margin-bottom: 8px;
+  border: 1px solid var(--border);
+  border-left: 3px solid var(--accent, #4a90d9);
+  border-radius: 4px;
+  background: var(--bg-secondary);
+  color: var(--text-secondary);
+  font-size: 0.82rem;
+  line-height: 1.45;
+}
+.xlsx-truncated-icon {
+  width: 16px;
+  height: 16px;
+  flex: 0 0 auto;
+  margin-top: 1px;
+  color: var(--accent, #4a90d9);
+}
+
+/* #153 A9bis — “charger la suite” footnote under a truncated sheet. Also the
+   scroll sentinel target: clickable whole, disabled look once the sheet is
+   fully loaded. */
+.xlsx-load-more {
+  display: block;
+  margin: 6px 0 10px;
+  padding: 6px 12px;
+  border: 1px dashed var(--border);
+  border-radius: 4px;
+  background: var(--bg-secondary);
+  color: var(--text-secondary);
+  font-size: 0.82rem;
+  text-align: center;
+  cursor: pointer;
+  user-select: none;
+}
+.xlsx-load-more:hover {
+  border-color: var(--accent, #4a90d9);
+  color: var(--text-primary);
+}
+.xlsx-load-more.done {
+  display: none;
+}
+
 .xlsx-formula-toggle {
   font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
   font-weight: 600;

package.json

@@ -1,6 +1,6 @@
 {
   "name": "obsigate",
-  "version": "2.29.0",
+  "version": "2.34.0",
   "description": "**Porte d'entrée web ultra-léger pour vos vaults Obsidian** — Accédez, naviguez et recherchez dans toutes vos notes Obsidian depuis n'importe quel appareil via une interface web moderne et responsive.",
   "main": "patch.js",
   "directories": {

tests/e2e/xlsx-viewer.spec.js

@@ -11,7 +11,14 @@
  *  - the warning banner lists both features ;
  *  - saving a cell on that workbook asks for confirmation (native dialog) and
  *    then succeeds (the client retries with `force: true`) ;
- *  - the f(x) toggle is off by default, so "=B1*3" is stored as text.
+ *  - the f(x) toggle is off by default, so "=B1*3" is stored as text ;
+ *  - the value Excel last computed is shown under the formula (#153 A12).
+ *
+ * Second describe block — `test_vault/sample-xlsx-large.xlsx` (520 rows) :
+ *  - a sheet over the render caps SAYS it instead of looking complete (#153 A8) ;
+ *  - the column headers stay pinned while the sheet scrolls (#153 A8) ;
+ *  - `GET …/xlsx/sheet?offset=500` serves the rows the caps used to hide,
+ *    with the real A1 coordinates (#153 A9).
  *
  * The fixture is restored byte-for-byte in `afterAll` so a local run never
  * dirties the working copy.
@@ -26,6 +33,10 @@ import path from 'node:path';
 const BASE = process.env.BASE_URL || 'http://localhost:2029';
 const VAULT = 'TestVault';
 const FIXTURE = 'sample-xlsx-lossy.xlsx';
+// #153 A8 — 520 rows x 3 columns: the sheet exceeds the 500-row render cap, so
+// the viewer must SAY so. Generated once with openpyxl (header + 519 lines) and
+// committed next to the other fixture; nothing in the suite writes to it.
+const LARGE = 'sample-xlsx-large.xlsx';
 // Playwright runs from the repository root (run-e2e-local.* / CI both do).
 const FIXTURE_PATH = path.resolve(process.cwd(), 'test_vault', FIXTURE);
 
@@ -44,7 +55,11 @@ async function login(page) {
 }
 
 async function openFixture(page) {
-  const treeItem = page.locator(`.tree-item[data-vault="${VAULT}"][data-path="${FIXTURE}"]`);
+  return openXlsx(page, FIXTURE);
+}
+
+async function openXlsx(page, file) {
+  const treeItem = page.locator(`.tree-item[data-vault="${VAULT}"][data-path="${file}"]`);
   if (!(await treeItem.count())) {
     await page.locator(`.tree-item.vault-item[data-vault="${VAULT}"]`).first().click();
     await treeItem.waitFor({ state: 'attached', timeout: 8000 });
@@ -53,7 +68,7 @@ async function openFixture(page) {
   await expect(page.locator('#content-area .xlsx-table')).toBeVisible({ timeout: 15000 });
 }
 
-test.describe('Excel viewer — garde-fous d\'écriture (#153 P0)', () => {
+test.describe('Excel viewer — garde-fous d\'écriture et valeurs calculées (#153)', () => {
   test.beforeAll(() => {
     if (existsSync(FIXTURE_PATH)) originalBytes = readFileSync(FIXTURE_PATH);
   });
@@ -62,6 +77,28 @@ test.describe('Excel viewer — garde-fous d\'écriture (#153 P0)', () => {
     if (originalBytes) writeFileSync(FIXTURE_PATH, originalBytes);
   });
 
+  // Read-only assertions come FIRST, before the mutating tests: saving through
+  // the viewer rewrites the workbook and an openpyxl round-trip drops the cached
+  // formula results (BUG-085), so the shadow line only exists on a pristine
+  // fixture.
+  test('affiche la valeur calculée en cache sous la formule (#153 A12)', async ({ page }) => {
+    await login(page);
+    await openFixture(page);
+
+    // B2 is "=B1*2" and the package keeps its last result (<v>200</v>).
+    const formulaCell = page.locator('#content-area td[data-cell="B2"]');
+    await expect(formulaCell).toContainText('=B1*2');
+
+    const cached = formulaCell.locator('.xlsx-cached');
+    await expect(cached).toHaveCount(1);
+    await expect(cached).toHaveText('200');
+    // The tooltip is translated client-side, never hardcoded by the backend.
+    await expect(cached).toHaveAttribute('title', /Excel/);
+
+    // A plain value cell must not be duplicated with a shadow line.
+    await expect(page.locator('#content-area td[data-cell="B1"] .xlsx-cached')).toHaveCount(0);
+  });
+
   test('affiche la bannière listant les éléments non préservés', async ({ page }) => {
     await login(page);
     await openFixture(page);
@@ -118,3 +155,104 @@ test.describe('Excel viewer — garde-fous d\'écriture (#153 P0)', () => {
     await expect(page.locator('.toast-success')).toBeVisible({ timeout: 10000 });
   });
 });
+
+// ── A8 — troncature annoncée + en-têtes figés ───────────────────────────────
+
+test.describe('Excel viewer — troncature et navigation (#153 A8/A9)', () => {
+  test('annonce la feuille tronquée au lieu de la couper en silence', async ({ page }) => {
+    await login(page);
+    await openXlsx(page, LARGE);
+
+    const note = page.locator('#content-area .xlsx-truncated');
+    await expect(note).toBeVisible();
+    // Libellé traduit (jamais de texte UI backend, jamais de couleur en dur).
+    await expect(note).toContainText('Feuille tronquée');
+    await expect(note).toContainText('500 lignes affichées sur 520');
+
+    // La dernière ligne rendue est la 500e ; les suivantes ne sont pas là.
+    await expect(page.locator('#content-area td[data-cell="A500"]')).toHaveCount(1);
+    await expect(page.locator('#content-area td[data-cell="A501"]')).toHaveCount(0);
+  });
+
+  test('garde les en-têtes de colonnes visibles au défilement', async ({ page }) => {
+    await login(page);
+    await openXlsx(page, LARGE);
+
+    const header = page.locator('#content-area .xlsx-table thead th').nth(1);
+    const before = await header.boundingBox();
+
+    await page.locator('#content-area .csv-table-wrapper').evaluate((el) => { el.scrollTop = 800; });
+    await expect.poll(async () => (await header.boundingBox()).y, { timeout: 5000 })
+      .toBeLessThanOrEqual(before.y + 1);
+
+    // Les numéros de ligne ne se superposent pas en haut à gauche (le `top: auto`
+    // de A8) et la première ligne de données reste lisible sous l'en-tête.
+    const first = await page.locator('#content-area th.xlsx-rownum').first().boundingBox();
+    const second = await page.locator('#content-area th.xlsx-rownum').nth(1).boundingBox();
+    expect(second.y - first.y).toBeGreaterThan(4);
+  });
+
+  test('l\'endpoint de fenêtre sert les lignes au-delà du plafond (#153 A9)', async ({ page }) => {
+    await login(page);
+    await openXlsx(page, LARGE);
+
+    const res = await page.request.get(
+      `${BASE}/api/file/${VAULT}/xlsx/sheet?path=${encodeURIComponent(LARGE)}&sheet=Journal&offset=500&limit=50`
+    );
+    expect(res.status()).toBe(200);
+    const win = await res.json();
+    expect(win.total_rows).toBe(520);
+    expect(win.offset).toBe(500);
+    expect(win.has_more).toBe(false);
+    // Les coordonnées A1 sont celles de la feuille, pas celles de la fenêtre :
+    // la ligne 520 est servie comme A520, pas comme A20.
+    expect(win.html).toContain('data-cell="A520"');
+    expect(win.html).toContain('Operation 519');
+    expect(win.html).not.toContain('data-cell="A1"');
+  });
+
+  test('le bouton « charger la suite » ajoute les lignes cachées (#153 A9bis)', async ({ page }) => {
+    await login(page);
+    await openXlsx(page, LARGE);
+
+    // La ligne 500 est la dernière rendue ; le pied de page l'annonce.
+    const foot = page.locator('#content-area .xlsx-load-more');
+    await expect(foot).toBeVisible();
+    await expect(foot).toContainText('Charger la suite');
+    await expect(page.locator('#content-area td[data-cell="A501"]')).toHaveCount(0);
+
+    // Un clic fetch la suite (offset 500, 20 lignes) et l'insère dans la table.
+    await foot.click();
+    await expect(page.locator('#content-area td[data-cell="A520"]')).toBeVisible({ timeout: 10000 });
+    // Une ligne nouvellement arrivée est éditable comme les autres.
+    const cell = page.locator('#content-area td[data-cell="A520"]');
+    await cell.click();
+    await expect(cell).toBeFocused();
+    // Tout est chargé → le pied de page est masqué.
+    await expect(foot).toBeHidden();
+  });
+
+  test('barre de formule et navigation clavier (#153 A7)', async ({ page }) => {
+    await login(page);
+    await openXlsx(page, LARGE);
+
+    // Un clic sur une cellule active la barre avec son nom et son contenu.
+    const cell = page.locator('#content-area td[data-cell="B2"]');
+    await cell.click();
+    await expect(page.locator('#xlsx-active-cell')).toHaveText('B2');
+    const bar = page.locator('#xlsx-formula-input');
+    await expect(bar).toHaveValue(/Operation 1/);
+
+    // Les flèches déplacent la cellule active.
+    await cell.press('ArrowDown');
+    await expect(page.locator('#xlsx-active-cell')).toHaveText('B3');
+    await page.locator('#content-area td[data-cell="B3"]').press('ArrowRight');
+    await expect(page.locator('#xlsx-active-cell')).toHaveText('C3');
+
+    // Éditer depuis la barre marque la cellule dirty, Échap annule.
+    await bar.fill('Operation 2 modifiee');
+    await expect(page.locator('#content-area td[data-cell="C3"]')).toHaveClass(/xlsx-dirty/);
+    await page.locator('#content-area td[data-cell="C3"]').press('Escape');
+    await expect(page.locator('#content-area td.xlsx-dirty')).toHaveCount(0);
+  });
+});

tests/frontend/xlsx-viewer.test.mjs

@@ -7,6 +7,12 @@
  *         workbook gets 409 `xlsx_lossy_content`, asks for confirmation and
  *         retries with `force: true` (or gives up when refused);
  *  - A4 : the f(x) toggle flips `allow_formula` in the save payload.
+ *  - A8 : a sheet bigger than the render caps shows the truncation notice.
+ *  - A9bis : the tail of a truncated sheet is fetched window by window from
+ *         GET …/xlsx/sheet (scroll sentinel + click), and the appended rows are
+ *         editable like the initial ones.
+ *  - A7 : formula bar mirrors the active cell; arrows/Tab navigate; editing
+ *         from the bar marks the cell dirty; Escape reverts.
  *
  * Usage: node tests/frontend/xlsx-viewer.test.mjs
  */
@@ -35,6 +41,7 @@ const dom = new JSDOM(
 const w = dom.window;
 globalThis.window = w;
 globalThis.document = w.document;
+globalThis.DOMParser = w.DOMParser;
 globalThis.HTMLElement = w.HTMLElement;
 globalThis.Element = w.Element;
 globalThis.Node = w.Node;
@@ -89,7 +96,11 @@ async function test(name, fn) {
   confirmCalls = 0;
   confirmPrompts = [];
   confirmAnswer = true;
-  nextResponse = () => ({ ok: true, status: 200, body: { status: "ok" } });
+  apiQueue = [];
+  nextResponse = () => {
+    if (apiQueue.length) return apiQueue.shift();
+    return { ok: true, status: 200, body: { status: "ok" } };
+  };
   try {
     await fn();
     console.log(`  ✓ ${name}`);
@@ -112,23 +123,36 @@ await initI18n();
 
 const sheetHtml = (value) =>
   '<div class="csv-table-wrapper"><table class="csv-table xlsx-table">' +
-  '<thead><tr><th class="xlsx-corner"></th><th>A</th></tr></thead><tbody>' +
-  `<tr><th class="xlsx-rownum">1</th><td data-cell="A1">${value}</td></tr>` +
+  '<thead><tr><th class="xlsx-corner"></th><th>A</th><th>B</th></tr></thead><tbody>' +
+  `<tr><th class="xlsx-rownum">1</th><td data-cell="A1">${value}</td><td data-cell="B1">B1</td></tr>` +
+  '<tr><th class="xlsx-rownum">2</th><td data-cell="A2">A2</td><td data-cell="B2">B2</td></tr>' +
   "</tbody></table></div>";
 
-function mount({ lossy = [] } = {}) {
+// The JSDOM fetch double serves locale files; everything else is a recorded
+// API call answered by `nextResponse`. `apiQueue` lets a test script the
+// successive windows a lazy-loading sheet will request.
+let apiQueue = [];
+
+function mount({ lossy = [], sheet = {} } = {}) {
   const area = document.getElementById("content-area");
   area.innerHTML = "";
   renderXlsxViewer(area, {
     vault: "V",
     path: "data.xlsx",
     is_xlsx: true,
-    xlsx_sheets: [{ name: "Feuille1", html: sheetHtml("100") }],
+    xlsx_sheets: [{ name: "Feuille1", html: sheetHtml("100"), ...sheet }],
     xlsx_lossy_features: lossy,
   });
   return area;
 }
 
+/** Mount a sheet flagged truncated so wireLazyRows() arms the footnote. */
+function mountTruncated({ total = 520, rows = 1 } = {}) {
+  return mount({
+    sheet: { rows, cols: 3, total_rows: total, total_cols: 3, max_rows: 500, max_cols: 40, truncated: total > 500 },
+  });
+}
+
 /** Mark a cell dirty the way a user edit would. */
 function editCell(area, ref, text) {
   const td = area.querySelector(`td[data-cell="${ref}"]`);
@@ -268,6 +292,231 @@ await test("a non-409 failure is not retried", async () => {
   assert.equal(area.querySelectorAll("td.xlsx-dirty").length, 1);
 });
 
+// ── A8 — truncation notice ───────────────────────────────────────────────────
+
+await test("no notice when the sheet fits within the render caps", () => {
+  const area = mount({
+    sheet: { rows: 500, cols: 40, total_rows: 500, total_cols: 40, max_rows: 500, max_cols: 40, truncated: false },
+  });
+  assert.equal(area.querySelector(".xlsx-truncated"), null);
+});
+
+await test("notice states the cap and the real size of a truncated sheet", () => {
+  const area = mount({
+    sheet: { rows: 500, cols: 12, total_rows: 1200, total_cols: 12, max_rows: 500, max_cols: 40, truncated: true },
+  });
+  const note = area.querySelector(".xlsx-truncated");
+  assert.ok(note, "notice absent");
+  const txt = note.textContent;
+  assert.ok(txt.includes(FR["xlsx.truncated_title"]), txt);
+  // {shown} is the CAP (500), not the post-trim row count: a sparse sheet
+  // renders 1 row but the view still reaches 500 of them.
+  const expected = FR["xlsx.truncated_rows"].replace("{shown}", "500").replace("{total}", "1200");
+  assert.ok(txt.includes(expected), `${txt} !includes ${expected}`);
+  // Nothing to say about the columns here (12 < 40).
+  assert.ok(!txt.includes(FR["xlsx.truncated_cols"]), txt);
+});
+
+await test("notice mentions both axes when rows AND columns overflow", () => {
+  const area = mount({
+    sheet: { rows: 1, cols: 40, total_rows: 501, total_cols: 45, max_rows: 500, max_cols: 40, truncated: true },
+  });
+  const txt = area.querySelector(".xlsx-truncated").textContent;
+  assert.ok(
+    txt.includes(FR["xlsx.truncated_cols"].replace("{shown}", "40").replace("{total}", "45")),
+    txt
+  );
+});
+
+await test("a payload without the dimensions shows no notice", () => {
+  // Backward compatibility: an older cached response must not produce "NaN".
+  const area = mount({ sheet: { name: "Feuille1" } });
+  assert.equal(area.querySelector(".xlsx-truncated"), null);
+  assert.ok(!area.textContent.includes("NaN"));
+});
+
+// ── A9bis — lazy loading of the truncated tail ──────────────────────────────
+
+const windowHtml = (from, to) =>
+  '<div class="csv-table-wrapper"><table class="csv-table xlsx-table">' +
+  "<tbody>" +
+  Array.from({ length: to - from + 1 }, (_, i) => {
+    const r = from + i;
+    return `<tr><th class="xlsx-rownum">${r}</th><td data-cell="A${r}">Ligne ${r}</td></tr>`;
+  }).join("") +
+  "</tbody></table></div>";
+
+await test("a truncated sheet gets a load-more footnote, a normal one does not", () => {
+  const truncated = mountTruncated();
+  assert.ok(truncated.querySelector(".xlsx-load-more"), "footnote absent");
+  assert.ok(truncated.querySelector(".xlsx-load-more").textContent.includes(FR["xlsx.load_more"]));
+
+  const plain = mount({ sheet: { rows: 10, cols: 2, total_rows: 10, total_cols: 2, max_rows: 500, max_cols: 40, truncated: false } });
+  assert.equal(plain.querySelector(".xlsx-load-more"), null);
+});
+
+await test("clicking the footnote fetches the next window with the right query", async () => {
+  const area = mountTruncated();
+  apiQueue.push({
+    ok: true,
+    status: 200,
+    body: { sheet: "Feuille1", offset: 1, limit: 500, rows: 2, total_rows: 3, truncated: true, has_more: false, html: windowHtml(2, 3) },
+  });
+  area.querySelector(".xlsx-load-more").click();
+  await new Promise((r) => setTimeout(r, 5));
+  assert.equal(calls.length, 1);
+  assert.match(calls[0].url, /\/api\/file\/V\/xlsx\/sheet\?path=data\.xlsx&sheet=Feuille1&offset=1&limit=500/);
+  // Rows 2 and 3 landed in the table with their real coordinates.
+  assert.ok(area.querySelector('td[data-cell="A2"]'));
+  assert.ok(area.querySelector('td[data-cell="A3"]'));
+  assert.ok(area.querySelector('th.xlsx-rownum') && area.textContent.includes("Ligne 3"));
+  // Everything loaded → the footnote is hidden (kept in the DOM, class `done`).
+  const foot = area.querySelector(".xlsx-load-more");
+  assert.ok(foot, "the footnote element survives");
+  assert.equal(foot.classList.contains("done"), true);
+  assert.ok(!foot.textContent.includes(FR["xlsx.load_more"]), foot.textContent);
+});
+
+await test("appended rows are editable and tracked as dirty", async () => {
+  const area = mountTruncated();
+  apiQueue.push({
+    ok: true,
+    status: 200,
+    body: { sheet: "Feuille1", offset: 1, limit: 500, rows: 1, total_rows: 3, truncated: true, has_more: false, html: windowHtml(2, 2) },
+  });
+  area.querySelector(".xlsx-load-more").click();
+  await new Promise((r) => setTimeout(r, 5));
+  editCell(area, "A2", "modifié");
+  area.querySelector("#xlsx-save-btn").click();
+  await new Promise((r) => setTimeout(r, 5));
+  assert.equal(calls.length, 2, "the save went out");
+  assert.equal(calls[1].url.includes("/xlsx/save"), true);
+  assert.deepEqual(calls[1].body.cells, { A2: "modifié" });
+  assert.equal(calls[1].body.sheet, "Feuille1");
+});
+
+await test("a failed window fetch keeps the footnote and shows an error toast", async () => {
+  const area = mountTruncated();
+  apiQueue.push({ ok: false, status: 500, body: { detail: "boom" } });
+  area.querySelector(".xlsx-load-more").click();
+  await new Promise((r) => setTimeout(r, 5));
+  const foot = area.querySelector(".xlsx-load-more");
+  assert.ok(foot, "footnote must survive a failed fetch");
+  assert.ok(foot.textContent.includes(FR["xlsx.load_more"]), foot.textContent);
+  // `api()` itself toasts the failure (shared behaviour, asserted in E2E);
+  // here we assert the local consequence: the footnote keeps its label.
+  // Retrying works once the server answers again.
+  apiQueue.push({
+    ok: true,
+    status: 200,
+    body: { sheet: "Feuille1", offset: 1, limit: 500, rows: 1, total_rows: 3, truncated: true, has_more: false, html: windowHtml(2, 2) },
+  });
+  foot.click();
+  await new Promise((r) => setTimeout(r, 5));
+  assert.ok(area.querySelector('td[data-cell="A2"]'));
+  assert.equal(area.querySelector(".xlsx-load-more").classList.contains("done"), true);
+});
+
+// ── A7 — formula bar & keyboard navigation ──────────────────────────────────
+
+await test("the formula bar starts empty and disabled", () => {
+  const area = mount();
+  assert.equal(area.querySelector("#xlsx-active-cell").textContent, "—");
+  assert.equal(area.querySelector("#xlsx-formula-input").disabled, true);
+});
+
+await test("focusing a cell shows its name and content in the bar", () => {
+  const area = mount();
+  const td = area.querySelector('td[data-cell="A1"]');
+  td.dispatchEvent(new w.Event("focus", { bubbles: false }));
+  // JSDOM does not run the default focus behaviour on dispatchEvent, so go
+  // through the real API:
+  td.focus();
+  assert.equal(area.querySelector("#xlsx-active-cell").textContent, "A1");
+  assert.equal(area.querySelector("#xlsx-formula-input").value, "100");
+  assert.equal(area.querySelector("#xlsx-formula-input").disabled, false);
+});
+
+await test("typing in the bar edits the cell live and marks it dirty", () => {
+  const area = mount();
+  const td = area.querySelector('td[data-cell="A1"]');
+  td.focus();
+  const input = area.querySelector("#xlsx-formula-input");
+  input.value = "depuis la barre";
+  input.dispatchEvent(new w.Event("input", { bubbles: true }));
+  assert.equal(td.textContent, "depuis la barre");
+  assert.equal(td.classList.contains("xlsx-dirty"), true);
+  assert.equal(area.querySelector("#xlsx-save-btn").disabled, false);
+  // The save payload carries the cell edit.
+  area.querySelector("#xlsx-save-btn").click();
+  return new Promise((r) => setTimeout(r, 5)).then(() => {
+    assert.deepEqual(calls[0].body.cells, { A1: "depuis la barre" });
+  });
+});
+
+await test("Tab and arrows move to the neighbour cell", () => {
+  const area = mount();
+  const a1 = area.querySelector('td[data-cell="A1"]');
+  a1.focus();
+  a1.dispatchEvent(new w.KeyboardEvent("keydown", { key: "Tab", bubbles: true }));
+  assert.equal(area.querySelector("#xlsx-active-cell").textContent, "B1");
+  const b1 = area.querySelector('td[data-cell="B1"]');
+  b1.dispatchEvent(new w.KeyboardEvent("keydown", { key: "ArrowDown", bubbles: true }));
+  assert.equal(area.querySelector("#xlsx-active-cell").textContent, "B2");
+  const b2 = area.querySelector('td[data-cell="B2"]');
+  b2.dispatchEvent(new w.KeyboardEvent("keydown", { key: "ArrowLeft", bubbles: true }));
+  assert.equal(area.querySelector("#xlsx-active-cell").textContent, "A2");
+});
+
+await test("Enter commits and Shift+Tab goes backwards", () => {
+  const area = mount();
+  const a1 = area.querySelector('td[data-cell="A1"]');
+  a1.focus();
+  a1.dispatchEvent(new w.KeyboardEvent("keydown", { key: "Tab", bubbles: true }));
+  const b1 = area.querySelector('td[data-cell="B1"]');
+  b1.dispatchEvent(new w.KeyboardEvent("keydown", { key: "Tab", shiftKey: true, bubbles: true }));
+  assert.equal(area.querySelector("#xlsx-active-cell").textContent, "A1");
+});
+
+await test("a saved edit from the bar resets the dirty flag and orig value", async () => {
+  const area = mount();
+  const td = area.querySelector('td[data-cell="A1"]');
+  td.focus();
+  const input = area.querySelector("#xlsx-formula-input");
+  input.value = "200";
+  input.dispatchEvent(new w.Event("input", { bubbles: true }));
+  area.querySelector("#xlsx-save-btn").click();
+  await new Promise((r) => setTimeout(r, 5));
+  assert.equal(area.querySelectorAll("td.xlsx-dirty").length, 0);
+  assert.equal(td.dataset.orig, "200");
+});
+
+await test("two windows in a row walk the whole sheet", async () => {
+  const area = mountTruncated({ total: 1200 });
+  apiQueue.push({
+    ok: true,
+    status: 200,
+    body: { sheet: "Feuille1", offset: 1, limit: 500, rows: 500, total_rows: 1200, truncated: true, has_more: true, html: windowHtml(2, 501) },
+  });
+  area.querySelector(".xlsx-load-more").click();
+  await new Promise((r) => setTimeout(r, 5));
+  assert.ok(area.querySelector('td[data-cell="A501"]'));
+  // The footnote still shows, with the updated progress.
+  let foot = area.querySelector(".xlsx-load-more");
+  assert.ok(foot, "more rows remain");
+  assert.ok(foot.textContent.includes("501"), foot.textContent);
+
+  apiQueue.push({
+    ok: true,
+    status: 200,
+    body: { sheet: "Feuille1", offset: 501, limit: 500, rows: 200, total_rows: 1200, truncated: true, has_more: false, html: windowHtml(502, 701) },
+  });
+  foot.click();
+  await new Promise((r) => setTimeout(r, 5));
+  assert.ok(area.querySelector('td[data-cell="A701"]'));
+  assert.equal(area.querySelector(".xlsx-load-more").classList.contains("done"), true);
+});
+
 // ── Report ──────────────────────────────────────────────────────────────────
 console.log(`\n${passCount}/${testCount} tests passed\n`);
 process.exit(passCount === testCount ? 0 : 1);

tests/test_spreadsheet_tools.py

@@ -0,0 +1,225 @@
+"""Unit tests for the existing-workbook AI tools (#153 A6).
+
+Covers ``list_xlsx_sheets``, ``xlsx_to_markdown``, ``update_xlsx_cells`` and
+``append_xlsx_rows`` — risk levels, confirmation gating, vault persistence and
+the reuse of the guarded mutation service (P0 guards, formula neutralisation).
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+from backend.tools.api import (
+    ToolConfirmationRequired,
+    ToolContext,
+    ToolError,
+    call_tool,
+    get_tool,
+)
+from backend.tools.context import ToolRisk
+
+openpyxl = pytest.importorskip("openpyxl")
+
+
+@pytest.fixture
+def vault(tmp_path, monkeypatch):
+    """A minimal configured vault (index entry patched, no full build)."""
+    vault_dir = tmp_path / "Vault"
+    vault_dir.mkdir()
+    monkeypatch.setitem(
+        __import__("backend.indexer", fromlist=["index"]).index,
+        "Vault",
+        {"name": "Vault", "path": str(vault_dir), "config": {}},
+    )
+    return vault_dir
+
+
+@pytest.fixture
+def workbook(vault: Path) -> Path:
+    """A two-sheet workbook: Budget (values + a formula) and Notes."""
+    path = vault / "classeur.xlsx"
+    wb = openpyxl.Workbook()
+    ws = wb.active
+    ws.title = "Budget"
+    ws.append(["Poste", "Montant"])
+    ws.append(["Loyer", 900])
+    ws.append(["Courses", 250])
+    notes = wb.create_sheet("Notes")
+    notes["A1"] = "bonjour"
+    wb.save(path)
+    return path
+
+
+def _ctx() -> ToolContext:
+    return ToolContext(
+        user={"username": "tester", "role": "admin", "vaults": ["*"]},
+        audit_enabled=False,
+    )
+
+
+class TestRegistry:
+    def test_read_tools_are_read_risk(self):
+        for name in ("list_xlsx_sheets", "xlsx_to_markdown"):
+            spec = get_tool(name)
+            assert spec is not None
+            assert spec.risk == ToolRisk.READ
+
+    def test_mutation_tools_require_confirmation(self):
+        for name in ("update_xlsx_cells", "append_xlsx_rows"):
+            spec = get_tool(name)
+            assert spec is not None
+            assert spec.risk == ToolRisk.WRITE
+            assert spec.requires_confirmation is True
+
+    def test_mutation_tools_raise_without_confirmation(self, vault, workbook):
+        with pytest.raises(ToolConfirmationRequired):
+            call_tool("update_xlsx_cells", _ctx(), {
+                "vault": "Vault", "path": "classeur.xlsx",
+                "sheet": "Budget", "cells": {"B3": "300"},
+            })
+        with pytest.raises(ToolConfirmationRequired):
+            call_tool("append_xlsx_rows", _ctx(), {
+                "vault": "Vault", "path": "classeur.xlsx",
+                "sheet": "Budget", "rows": [["Total", 1150]],
+            })
+
+
+class TestListXlsxSheets:
+    def test_lists_names_and_dimensions(self, vault, workbook):
+        out = call_tool("list_xlsx_sheets", _ctx(), {
+            "vault": "Vault", "path": "classeur.xlsx",
+        })
+        assert out.ok
+        data = out.data
+        assert [s["name"] for s in data["sheets"]] == ["Budget", "Notes"]
+        budget = data["sheets"][0]
+        assert budget["total_rows"] == 3 and budget["total_cols"] == 2
+        assert budget["truncated"] is False
+
+    def test_wrong_extension_rejected(self, vault):
+        with pytest.raises(ToolError):
+            call_tool("list_xlsx_sheets", _ctx(), {
+                "vault": "Vault", "path": "note.md",
+            })
+
+    def test_missing_file_rejected(self, vault):
+        with pytest.raises(ToolError):
+            call_tool("list_xlsx_sheets", _ctx(), {
+                "vault": "Vault", "path": "absent.xlsx",
+            })
+
+
+class TestXlsxToMarkdown:
+    def test_renders_a_bounded_markdown_table(self, vault, workbook):
+        out = call_tool("xlsx_to_markdown", _ctx(), {
+            "vault": "Vault", "path": "classeur.xlsx",
+        })
+        assert out.ok
+        data = out.data
+        assert data["sheet"] == "Budget"
+        assert data["rows"] == 3 and data["truncated"] is False
+        assert "| Poste | Montant |" in data["markdown"]
+        assert "| Loyer | 900 |" in data["markdown"]
+
+    def test_specific_sheet(self, vault, workbook):
+        out = call_tool("xlsx_to_markdown", _ctx(), {
+            "vault": "Vault", "path": "classeur.xlsx", "sheet": "Notes",
+        })
+        assert out.ok
+        data = out.data
+        assert data["sheet"] == "Notes"
+        assert "bonjour" in data["markdown"]
+
+    def test_unknown_sheet_rejected(self, vault, workbook):
+        with pytest.raises(ToolError):
+            call_tool("xlsx_to_markdown", _ctx(), {
+                "vault": "Vault", "path": "classeur.xlsx", "sheet": "Nope",
+            })
+
+    def test_big_sheet_is_flagged_truncated(self, vault):
+        path = vault / "gros.xlsx"
+        wb = openpyxl.Workbook()
+        ws = wb.active
+        for i in range(150):
+            ws.append([f"r{i}", i])
+        wb.save(path)
+        out = call_tool("xlsx_to_markdown", _ctx(), {
+            "vault": "Vault", "path": "gros.xlsx",
+        })
+        assert out.ok
+        data = out.data
+        assert data["rows"] == 100
+        assert data["truncated"] is True
+
+
+class TestUpdateXlsxCells:
+    def test_edits_cells_and_survives_a_reload(self, vault, workbook):
+        out = call_tool("update_xlsx_cells", _ctx(), {
+            "vault": "Vault", "path": "classeur.xlsx",
+            "sheet": "Budget", "cells": {"B3": "300"},
+        }, confirm=True)
+        assert out.ok and out.data["status"] == "ok"
+        wb = openpyxl.load_workbook(workbook)
+        assert wb["Budget"]["B3"].value == 300  # coerced like the viewer
+        wb.close()
+
+    def test_formula_stays_text_by_default(self, vault, workbook):
+        out = call_tool("update_xlsx_cells", _ctx(), {
+            "vault": "Vault", "path": "classeur.xlsx",
+            "sheet": "Budget", "cells": {"C1": "=B2+B3"},
+        }, confirm=True)
+        assert out.ok
+        wb = openpyxl.load_workbook(workbook)
+        assert wb["Budget"]["C1"].data_type == "s"  # A4 guard inherited
+        wb.close()
+
+    def test_empty_cells_rejected(self, vault, workbook):
+        with pytest.raises(ToolError):
+            call_tool("update_xlsx_cells", _ctx(), {
+                "vault": "Vault", "path": "classeur.xlsx",
+                "sheet": "Budget", "cells": {},
+            })
+
+
+class TestAppendXlsxRows:
+    def test_appends_below_the_last_row(self, vault, workbook):
+        out = call_tool("append_xlsx_rows", _ctx(), {
+            "vault": "Vault", "path": "classeur.xlsx",
+            "sheet": "Budget", "rows": [["Total", 1150]],
+        }, confirm=True)
+        assert out.ok
+        assert out.data["first_row"] == 4
+        wb = openpyxl.load_workbook(workbook)
+        ws = wb["Budget"]
+        assert ws["A4"].value == "Total"
+        assert ws["B4"].value == 1150 and isinstance(ws["B4"].value, int)
+        wb.close()
+
+    def test_values_are_coerced(self, vault, workbook):
+        out = call_tool("append_xlsx_rows", _ctx(), {
+            "vault": "Vault", "path": "classeur.xlsx",
+            "sheet": "Budget", "rows": [["VRAI", "01/02/2026", 12.5]],
+        }, confirm=True)
+        assert out.ok
+        wb = openpyxl.load_workbook(workbook)
+        ws = wb["Budget"]
+        assert ws["A4"].value is True
+        assert (ws["B4"].value.month, ws["B4"].value.day) == (2, 1)
+        assert ws["C4"].value == 12.5
+        wb.close()
+
+    def test_unknown_sheet_rejected(self, vault, workbook):
+        with pytest.raises(ToolError):
+            call_tool("append_xlsx_rows", _ctx(), {
+                "vault": "Vault", "path": "classeur.xlsx",
+                "sheet": "Nope", "rows": [["x"]],
+            })
+
+    def test_empty_rows_rejected(self, vault, workbook):
+        with pytest.raises(ToolError):
+            call_tool("append_xlsx_rows", _ctx(), {
+                "vault": "Vault", "path": "classeur.xlsx",
+                "sheet": "Budget", "rows": [],
+            })

tests/test_xlsx_viewer.py

@@ -106,16 +106,208 @@ class TestXlsxIndexing:
 
         assert ".xlsx" in SUPPORTED_EXTENSIONS
 
-    def test_xlsx_indexed_metadata_only(self, test_vault_dir, xlsx_file):
+    def test_xlsx_indexes_sheet_names_and_headers(self, test_vault_dir, xlsx_file):
+        """#153 A5 — a workbook is searchable by its cell values."""
         from backend.indexer import _index_single_file_sync
 
         info = _index_single_file_sync(VAULT, test_vault_dir, xlsx_file)
         assert info is not None
         assert info["extension"] == ".xlsx"
-        assert info["content"] == ""  # binary: never read into TF-IDF
+        # Sheet names + header rows reach TF-IDF (was metadata-only before A5).
+        assert "Budget" in info["content"]
+        assert "Poste" in info["content"]
+        assert info["content_preview"]
         assert info["title"]  # filename-derived title
 
 
+class TestXlsxCachedValues:
+    """#153 A12 — show what Excel last computed next to each formula."""
+
+    def test_cached_result_is_shown_beside_the_formula(self, client, lossy_xlsx):
+        from backend.xlsx_reader import render_sheets
+
+        html = render_sheets(Path(lossy_xlsx))[0]["html"]
+        # A2 is "=A1*3" with <v>9</v> in the fixture.
+        assert 'data-cell="A2"' in html
+        assert "=A1*3" in html
+        assert "xlsx-cached" in html
+        assert ">9<" in html  # the cached result Excel computed
+
+    def test_no_shadow_when_no_formula_carries_a_result(self, client, xlsx_file):
+        from backend.xlsx_reader import render_sheets
+
+        html = render_sheets(Path(xlsx_file))[0]["html"]
+        assert "xlsx-cached" not in html  # budget.xlsx has no <v> at all
+
+    def test_plain_cells_are_never_duplicated(self, client, lossy_xlsx):
+        from backend.xlsx_reader import render_sheets
+
+        html = render_sheets(Path(lossy_xlsx))[0]["html"]
+        # A1 is the literal 3: the two reads agree, so only one value shows.
+        assert 'data-cell="A1"' in html
+        assert html.count("xlsx-cached") == 1  # only the formula cell
+
+
+class TestXlsxValueCoercion:
+    """#153 A10 — a typed value comes back with the type Excel would infer."""
+
+    def _write(self, client, xlsx_file, ref, value):
+        return client.put(
+            f"/api/file/{VAULT}/xlsx/save",
+            params={"path": "budget.xlsx"},
+            json={"sheet": "Budget", "cells": {ref: value}, "force": True},
+        )
+
+    def test_number_and_bool_are_stored_as_typed(self, client, xlsx_file):
+        resp = self._write(
+            client, xlsx_file, "D1", "42"
+        )
+        assert resp.status_code == 200
+        resp = self._write(client, xlsx_file, "D2", "VRAI")
+        assert resp.status_code == 200
+        resp = self._write(client, xlsx_file, "D3", "12/03/2026")
+        assert resp.status_code == 200
+
+        from openpyxl import load_workbook
+
+        wb = load_workbook(xlsx_file)
+        ws = wb["Budget"]
+        assert ws["D1"].value == 42 and isinstance(ws["D1"].value, int)
+        assert ws["D2"].value is True
+        assert ws["D3"].value.year == 2026 and ws["D3"].value.month == 3
+        assert ws["D3"].value.day == 12  # FR day-first, not 3 December
+        wb.close()
+
+    def test_day_first_date_is_not_read_as_us(self, client, xlsx_file):
+        """'01/02/2026' is 1 February in French, not 2 January."""
+        assert self._write(client, xlsx_file, "E1", "01/02/2026").status_code == 200
+        from openpyxl import load_workbook
+
+        wb = load_workbook(xlsx_file)
+        d = wb["Budget"]["E1"].value
+        wb.close()
+        assert (d.month, d.day) == (2, 1)
+
+    def test_ambiguous_text_is_left_alone(self, client, xlsx_file):
+        """A version string or a partial date stays text, never a date."""
+        assert self._write(client, xlsx_file, "F1", "3.14.2").status_code == 200
+        assert self._write(client, xlsx_file, "F2", "Ref 12/34").status_code == 200
+        assert self._write(client, xlsx_file, "F3", "12/2026").status_code == 200
+        from openpyxl import load_workbook
+
+        wb = load_workbook(xlsx_file)
+        ws = wb["Budget"]
+        assert ws["F1"].value == "3.14.2"
+        assert ws["F2"].value == "Ref 12/34"
+        assert ws["F3"].value == "12/2026"
+        wb.close()
+
+    def test_plain_integer_text_becomes_a_number(self, client, xlsx_file):
+        """Typing a bare number yields a number, as it did before #153 A10."""
+        assert self._write(client, xlsx_file, "H1", "75001").status_code == 200
+        from openpyxl import load_workbook
+
+        wb = load_workbook(xlsx_file)
+        assert wb["Budget"]["H1"].value == 75001
+        wb.close()
+
+    def test_formula_looking_date_stays_text(self, client, xlsx_file):
+        """A formula is never mistaken for a date (BUG-088 must not regress)."""
+        assert self._write(client, xlsx_file, "G1", "=12/03/2026").status_code == 200
+        from openpyxl import load_workbook
+
+        wb = load_workbook(xlsx_file)
+        c = wb["Budget"]["G1"]
+        wb.close()
+        assert c.data_type == "s"
+        assert c.value == "=12/03/2026"
+
+
+class TestXlsxSearchable:
+    """#153 A5 — a keyword living in a CELL must make the file findable."""
+
+    def test_search_finds_a_word_stored_in_a_cell(self, test_vault_dir):
+        """A word typed in a CELL must make the workbook findable.
+
+        Deliberately hermetic: it drives the indexer and the inverted index
+        directly instead of going through the HTTP reload, because both are
+        process-wide singletons that other test modules mutate (some reload the
+        module outright), which would make this test order-dependent.
+        """
+        from openpyxl import Workbook
+
+        import backend.indexer as indexer
+        import backend.search as search_mod
+
+        path = Path(test_vault_dir) / "fournisseurs.xlsx"
+        wb = Workbook()
+        ws = wb.active
+        ws.title = "Contacts"
+        ws["A1"] = "Fournisseur"
+        ws["A2"] = "Menuiserie Beaulieu"
+        wb.save(path)
+
+        # Index exactly this vault, from scratch.
+        indexer.index[VAULT] = {
+            "files": [indexer._index_single_file_sync(VAULT, test_vault_dir, str(path))],
+            "tags": {},
+            "paths": [],
+            "config": {},
+        }
+        entries = [f for f in indexer.index[VAULT]["files"] if f]
+        assert entries, "le tableur n'a pas ete indexe"
+        assert "Menuiserie" in entries[0]["content"], (
+            f"contenu indexe : {entries[0]['content'][:80]!r}"
+        )
+
+        search_mod.init_inverted_index()
+        hits = [r["path"] for r in search_mod.search("Menuiserie", "all")]
+        assert "fournisseurs.xlsx" in hits
+
+    def test_indexable_text_is_capped(self, tmp_path):
+        """A data dump must not flood the index."""
+        from openpyxl import Workbook
+
+        from backend.xlsx_reader import MAX_INDEX_CHARS, extract_indexable_text
+
+        path = tmp_path / "huge.xlsx"
+        wb = Workbook()
+        ws = wb.active
+        ws.title = "Big"
+        for r in range(1, 400):
+            ws.cell(row=r, column=1, value=f"ligne {r} " + "x" * 60)
+        wb.save(path)
+
+        text = extract_indexable_text(path)
+        assert len(text) <= MAX_INDEX_CHARS
+        assert "Big" in text  # the sheet name survives
+
+    def test_corrupt_workbook_indexes_as_empty_not_a_crash(self, tmp_path):
+        from backend.xlsx_reader import extract_indexable_text
+
+        path = tmp_path / "broken.xlsx"
+        path.write_bytes(b"not a zip at all")
+        assert extract_indexable_text(path) == ""
+
+    def test_blank_rows_are_skipped(self, tmp_path):
+        from openpyxl import Workbook
+
+        from backend.xlsx_reader import extract_indexable_text
+
+        path = tmp_path / "sparse.xlsx"
+        wb = Workbook()
+        ws = wb.active
+        ws.title = "S"
+        ws["A1"] = "Alpha"
+        ws["A50"] = "Omega"  # beyond the indexed prefix -> ignored on purpose
+        wb.save(path)
+
+        text = extract_indexable_text(path)
+        assert "Alpha" in text
+        assert "Omega" not in text
+        assert "\t\t" not in text  # no run of empty columns
+
+
 # ── Edit ──────────────────────────────────────────────────────────────────
 
 
@@ -327,6 +519,173 @@ class TestXlsxWriteLock:
         assert openpyxl.load_workbook(xlsx_file)["Budget"]["A1"].value == "premier"
 
 
+@pytest.fixture
+def wide_xlsx(test_vault_dir: str) -> str:
+    """Workbook whose sheet exceeds BOTH render caps (501 rows x 45 cols).
+
+    Sparse on purpose: a cell in A501 and one in AS1 are enough for openpyxl
+    to declare those dimensions, without writing 20 000 cells to disk.
+    """
+    from openpyxl import Workbook
+
+    path = Path(test_vault_dir) / "grand.xlsx"
+    wb = Workbook()
+    ws = wb.active
+    ws.title = "Data"
+    ws["A1"] = "tête"
+    ws["A501"] = "dernière ligne"
+    ws["AS1"] = "colonne 45"
+    wb.save(path)
+    return str(path)
+
+
+@pytest.fixture
+def edge_xlsx(test_vault_dir: str) -> str:
+    """Sheet exactly on the caps (500 rows x 40 cols) — must NOT be truncated."""
+    from openpyxl import Workbook
+
+    path = Path(test_vault_dir) / "limite.xlsx"
+    wb = Workbook()
+    ws = wb.active
+    ws.title = "Data"
+    ws["A1"] = "bord"
+    ws["A500"] = "ligne 500"
+    ws["AN1"] = "colonne 40"
+    wb.save(path)
+    return str(path)
+
+
+# ── #153 A8 — silent truncation made visible ─────────────────────────────
+
+
+class TestXlsxTruncationNotice:
+    """A sheet bigger than the caps must SAY so instead of looking complete."""
+
+    def test_render_reports_the_real_dimensions(self, client, wide_xlsx):
+        resp = client.get(f"/api/file/{VAULT}", params={"path": "grand.xlsx"})
+        sheet = resp.json()["xlsx_sheets"][0]
+        assert (sheet["total_rows"], sheet["total_cols"]) == (501, 45)
+        assert sheet["truncated"] is True
+        # The caps are the coverage the banner announces — `rows`/`cols` are
+        # post-trim and would understate it on a sparse sheet.
+        assert (sheet["max_rows"], sheet["max_cols"]) == (500, 40)
+        assert (sheet["rows"], sheet["cols"]) == (1, 1)  # only 3 filled cells
+
+    def test_a_sheet_on_the_caps_is_not_flagged(self, client, edge_xlsx):
+        """Boundary: 500x40 is exactly what the renderer supports."""
+        resp = client.get(f"/api/file/{VAULT}", params={"path": "limite.xlsx"})
+        sheet = resp.json()["xlsx_sheets"][0]
+        assert sheet["truncated"] is False
+        assert (sheet["total_rows"], sheet["total_cols"]) == (500, 40)
+
+    def test_a_normal_sheet_is_not_flagged(self, client, xlsx_file):
+        resp = client.get(f"/api/file/{VAULT}", params={"path": "budget.xlsx"})
+        assert all(not s["truncated"] for s in resp.json()["xlsx_sheets"])
+
+    def test_blank_tail_is_not_reported_as_truncation(self, client, test_vault_dir):
+        """A sheet with empty rows below its data fits in the caps."""
+        from openpyxl import Workbook
+
+        path = Path(test_vault_dir) / "blanc.xlsx"
+        wb = Workbook()
+        ws = wb.active
+        ws.title = "Data"
+        ws["A1"] = "seule ligne"
+        ws["A300"] = None  # formatted-but-empty row inside the caps
+        wb.save(path)
+        resp = client.get(f"/api/file/{VAULT}", params={"path": "blanc.xlsx"})
+        sheet = resp.json()["xlsx_sheets"][0]
+        assert sheet["truncated"] is False
+        assert sheet["rows"] == 1  # trailing blanks dropped by _trim
+
+
+# ── #153 A9 — lazy per-sheet loading ─────────────────────────────────────
+
+
+class TestXlsxSheetWindow:
+    """GET /api/file/{vault}/xlsx/sheet — one window of one sheet."""
+
+    def _get(self, client, path="budget.xlsx", **params):
+        return client.get(
+            f"/api/file/{VAULT}/xlsx/sheet", params={"path": path, **params}
+        )
+
+    def test_window_returns_rows_and_totals(self, client, xlsx_file):
+        resp = self._get(client, sheet="Budget", offset=0, limit=10)
+        assert resp.status_code == 200
+        data = resp.json()
+        assert data["sheet"] == "Budget"
+        assert (data["offset"], data["limit"]) == (0, 10)
+        assert data["rows"] == 2 and data["cols"] == 2
+        assert data["total_rows"] == 2 and data["truncated"] is False
+        assert (data["max_rows"], data["max_cols"]) == (500, 40)
+        assert data["has_more"] is False
+        assert 'data-cell="A1"' in data["html"]
+
+    def test_window_keeps_the_real_a1_coordinates(self, client, xlsx_file):
+        """A window must be indistinguishable from a full render: the A1
+        references and the row numbers have to be the sheet's, not the
+        window's, or an edit would land on the wrong cell. The CONTENT matters
+        as much as the label — row 2 of "Budget" is "Total", not "Poste"."""
+        data = self._get(client, sheet="Budget", offset=1, limit=1).json()
+        assert data["rows"] == 1
+        assert 'data-cell="A2"' in data["html"]
+        assert 'data-cell="A1"' not in data["html"]
+        assert "<th class=\"xlsx-rownum\">2</th>" in data["html"]
+        assert "Total" in data["html"] and "Poste" not in data["html"]
+
+    def test_window_offsets_walk_the_whole_sheet(self, client, wide_xlsx):
+        first = self._get(client, path="grand.xlsx", sheet="Data", offset=0, limit=10).json()
+        last = self._get(client, path="grand.xlsx", sheet="Data", offset=500, limit=10).json()
+        assert first["truncated"] is True and first["has_more"] is True
+        assert 'data-cell="A501"' in last["html"]  # the row the caps used to hide
+        assert "dernière ligne" in last["html"]
+        assert "dernière ligne" not in first["html"]
+        assert last["rows"] == 1 and last["has_more"] is False
+
+    def test_offset_past_the_end_is_empty_not_an_error(self, client, xlsx_file):
+        resp = self._get(client, sheet="Budget", offset=9999, limit=10)
+        assert resp.status_code == 200
+        data = resp.json()
+        assert data["rows"] == 0
+        assert data["has_more"] is False
+
+    def test_cached_result_survives_the_window(self, client, lossy_xlsx):
+        """A12 must not be lost on the lazy path."""
+        data = self._get(client, path="risky.xlsx", sheet="Data", offset=0, limit=10).json()
+        assert "xlsx-cached" in data["html"]
+
+    def test_unknown_sheet_is_404(self, client, xlsx_file):
+        resp = self._get(client, sheet="Nope")
+        assert resp.status_code == 404
+        assert "Feuille introuvable" in resp.json()["detail"]
+
+    def test_missing_file_is_404(self, client, test_vault_dir):
+        assert self._get(client, path="absent.xlsx", sheet="Budget").status_code == 404
+
+    def test_non_xlsx_file_is_415(self, client, test_vault_dir):
+        (Path(test_vault_dir) / "note.md").write_text("# hi", encoding="utf-8")
+        resp = self._get(client, path="note.md", sheet="Budget")
+        assert resp.status_code == 415
+
+    def test_limit_above_the_server_cap_is_rejected(self, client, xlsx_file):
+        """The cap is a contract, not a silent truncation of the request."""
+        assert self._get(client, sheet="Budget", limit=100_000).status_code == 422
+
+    def test_reader_clamps_a_hostile_limit(self, xlsx_file):
+        """Belt and braces: the reader caps too, whoever calls it."""
+        from backend.xlsx_reader import MAX_WINDOW_ROWS, read_sheet_window
+
+        window = read_sheet_window(Path(xlsx_file), "Budget", offset=0, limit=10**9)
+        assert window["limit"] == MAX_WINDOW_ROWS
+
+    def test_reader_rejects_a_negative_offset(self, xlsx_file):
+        from backend.xlsx_reader import read_sheet_window
+
+        window = read_sheet_window(Path(xlsx_file), "Budget", offset=-5, limit=10)
+        assert window["offset"] == 0
+
+
 # ── #153 A4 — formula injection ──────────────────────────────────────────