feat: structure des classeurs Excel editable depuis la visionneuse #153

A14 : service mutate_xlsx_structure (batch ordonné d'actions
sheet_add/sheet_rename/sheet_delete/sheet_duplicate et
row/col_insert/delete, une seule réécriture verrouillée et atomique,
409 lossy sans force, backup, dernier sheet protégé) ; endpoint
PUT /api/file/{vault}/xlsx/structure (1-50 actions/requête) ;
menu « structure » dans la visionneuse : ajout/renommage/duplication/
suppression de feuilles et insertion/suppression de ligne/colonne à
partir de la cellule active, confirmations explicites pour les
destructions, re-rendu serveur après succès, reprise force après
confirmation 409.

Vérifié : test_xlsx_structure.py 11 (ops, gardes, atomicité du batch,
409 lossy + force) + contre-preuve (garde dernier sheet neutralisée ->
1 échec), xlsx-viewer.test.mjs 33/33 (3 nouveaux), ruff 0, mypy 0,
i18n parity, validate-imports.

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

backend/routers/files_write.py

@@ -64,6 +64,9 @@ from backend.services.mutations import (
 from backend.services.mutations import (
     move_path as service_move_path,
 )
+from backend.services.mutations import (
+    mutate_xlsx_structure as service_mutate_xlsx_structure,
+)
 from backend.services.mutations import (
     rename_directory as service_rename_directory,
 )
@@ -174,6 +177,61 @@ def api_file_xlsx_save(
     return {"status": "ok", "vault": result["vault"], "path": result["path"], "size": result["size"]}
 
 
+@router.put("/api/file/{vault_name}/xlsx/structure", response_model=FileSaveResponse)
+def api_file_xlsx_structure(
+    vault_name: str,
+    path: str = Query(..., description="Relative path to the .xlsx file"),
+    body: dict = Body(
+        ...,
+        description=(
+            '{"actions": [{"op": "sheet_add", "name": "X"}, '
+            '{"op": "row_insert", "sheet": "X", "at": 2, "count": 1}], '
+            '"force": false}'
+        ),
+    ),
+    current_user=Depends(require_auth),
+):
+    """Apply structural changes to an .xlsx workbook (#153 A14).
+
+    ``actions`` is an ordered list applied in one locked, atomic rewrite:
+    ``sheet_add`` (``name``, optional ``at`` 0-based), ``sheet_rename``
+    (``from``/``to``), ``sheet_delete`` (refused on the last sheet),
+    ``sheet_duplicate`` (``name``/``as``) and ``row_insert``/``row_delete``/
+    ``col_insert``/``col_delete`` (``sheet``, 1-based ``at``, ``count``).
+
+    Without ``force`` the call fails **409** ``xlsx_lossy_content`` when the
+    workbook carries features openpyxl cannot rewrite (same gate as the cell
+    edits). A backup is created before the archive is replaced.
+
+    Args:
+        vault_name: Name of the vault.
+        path: Relative path to the ``.xlsx`` file.
+        body: JSON body with ``actions`` (1 to 50) and optional ``force``.
+
+    Returns:
+        ``FileSaveResponse`` confirming the write.
+    """
+    if not check_vault_access(vault_name, current_user):
+        raise HTTPException(status_code=403, detail=f"Accès refusé à la vault '{vault_name}'")
+
+    actions = body.get("actions")
+    if not isinstance(actions, list) or not actions or len(actions) > 50:
+        raise HTTPException(status_code=400, detail="Actions invalides (1 à 50 par requête)")
+    raw_force = body.get("force", False)
+    if not isinstance(raw_force, bool):
+        raise HTTPException(status_code=400, detail="Flag invalide: force")
+
+    result = service_mutate_xlsx_structure(
+        vault_name, path, actions, force=raw_force
+    )
+    log_file_save(
+        current_user["username"], vault_name, path,
+        len(actions),
+        current_user.get("_request_ip", "unknown"),
+    )
+    return {"status": "ok", "vault": result["vault"], "path": result["path"], "size": len(result["applied"])}
+
+
 @router.delete("/api/file/{vault_name}", response_model=FileDeleteResponse)
 async def api_file_delete(vault_name: str, path: str = Query(..., description="Relative path to file"), current_user=Depends(require_auth)):
     """Delete a file from the vault.