fix(ai): contexte applicatif de l'assistant, dossier vide et liens fiables (#88, BUG-041, BUG-042)

- BUG-041 : le contexte d'un dossier vide ne renvoie plus 404 ; il degrade
  vers le prompt General enrichi d'un bloc « Dossier vide ».
- BUG-042 : liens de fichiers deterministes (nom -> presse-papiers,
  dossier -> arborescence, chemin -> viewer) et resolution du chemin contre
  l'index du vault (exact -> suffixe -> basename) avant ouverture, fin des
  'File not found'.
- #88 : app_context (documents ouverts, repertoire/vault courants, recherche
  + resultats affiches) et fichiers recemment modifies injectes dans le
  prompt General.

Tests : pytest 963 passed / 6 skipped, ruff 0, mypy 0, frontend 52/52 +
validate-imports 36 modules.

backend/bookslm.py

@@ -499,13 +499,84 @@ Règles :
 """
 
 
-def build_general_system_prompt(vaults: list[str] | None = None) -> str:
-    """System prompt for the General assistant (app help + actions)."""
+def _format_app_context(app_context: dict[str, Any] | None, recent_files: list[dict[str, Any]] | None) -> str:
+    """Render the live application state for the General assistant prompt.
+
+    The General assistant has no document context; without this block it only
+    knows the app exists. Passing what the user currently sees (open documents,
+    current directory, active search, recently modified files) lets it answer
+    "résume ce que je fais / où j'en suis" style questions.
+    """
+    app_context = app_context or {}
+    lines: list[str] = []
+
+    vault = app_context.get("vault") or app_context.get("current_vault")
+    if vault:
+        lines.append(f"- Vault sélectionné : {vault}")
+    directory = app_context.get("directory")
+    if directory:
+        lines.append(f"- Répertoire courant : {directory}")
+    current_path = app_context.get("current_path")
+    if current_path:
+        lines.append(f"- Document affiché dans le viewer : {current_path}")
+
+    docs = app_context.get("open_documents") or []
+    rendered_docs = []
+    for doc in docs:
+        if not isinstance(doc, dict) or not doc.get("path"):
+            continue
+        rendered_docs.append(f"{doc['path']} (vault {doc['vault']})" if doc.get("vault") else str(doc["path"]))
+    if rendered_docs:
+        lines.append("- Documents ouverts dans les onglets/panneaux : " + ", ".join(rendered_docs))
+
+    query = app_context.get("search_query")
+    if query:
+        total = app_context.get("search_total")
+        suffix = f" ({total} résultat(s))" if isinstance(total, int) else ""
+        lines.append(f"- Recherche en cours : « {query} »{suffix}")
+
+    results = app_context.get("search_results") or []
+    rendered_results = [str(r.get("path")) for r in results[:10] if isinstance(r, dict) and r.get("path")]
+    if rendered_results:
+        lines.append("- Premiers résultats affichés : " + ", ".join(rendered_results))
+
+    if recent_files:
+        rendered_recent = [
+            f"{f.get('vault')}/{f.get('path')}" for f in recent_files[:10] if f.get("path")
+        ]
+        if rendered_recent:
+            lines.append("- Fichiers récemment modifiés : " + ", ".join(rendered_recent))
+
+    if not lines:
+        return ""
+    return (
+        "## Contexte applicatif actuel\n"
+        "Voici ce que l'utilisateur voit ou fait en ce moment dans ObsiGate. "
+        "Sers-t'en pour comprendre sa demande ; ne le répète pas inutilement.\n"
+        + "\n".join(lines)
+        + "\n"
+    )
+
+
+def build_general_system_prompt(
+    vaults: list[str] | None = None,
+    app_context: dict[str, Any] | None = None,
+    recent_files: list[dict[str, Any]] | None = None,
+) -> str:
+    """System prompt for the General assistant (app help + actions).
+
+    ``app_context`` carries the live UI state (open documents, current
+    directory, active search) and ``recent_files`` the last modified files, so
+    the assistant knows what the user is doing rather than answering blind.
+    """
     prompt = GENERAL_SYSTEM_PROMPT
     if vaults:
         prompt += "\nVaults disponibles : " + ", ".join(sorted(vaults)) + "\n"
     else:
         prompt += "\nAucun vault n'est actuellement configuré.\n"
+    block = _format_app_context(app_context, recent_files)
+    if block:
+        prompt += "\n" + block
     return prompt
 
 

backend/bookslm_routes.py

@@ -53,6 +53,11 @@ class BooksLMContextRequest(BaseModel):
         default_factory=list,
         description="Ad-hoc directories added with the '@' command (any mode)",
     )
+    app_context: dict[str, Any] | None = Field(
+        default=None,
+        description="Live client UI state for the General assistant: open_documents, "
+                    "current_path, directory, vault, search_query, search_total, search_results.",
+    )
 
 
 class BooksLMChatRequest(BaseModel):
@@ -104,6 +109,11 @@ class BooksLMChatRequest(BaseModel):
         description="Conversation snapshot returned alongside a ``confirmation`` event, "
                     "echoed back to resume the agent run.",
     )
+    app_context: dict[str, Any] | None = Field(
+        default=None,
+        description="Live client UI state for the General assistant: open_documents, "
+                    "current_path, directory, vault, search_query, search_total, search_results.",
+    )
 
 
 def _normalize_mode(mode: str | None) -> str:
@@ -154,6 +164,34 @@ def _build_context(
     return base
 
 
+def _submitted_app_context(req) -> dict[str, Any] | None:
+    """Return the client-submitted live app state (may be None)."""
+    ctx = getattr(req, "app_context", None)
+    return ctx if isinstance(ctx, dict) else None
+
+
+def _recent_files_for_prompt(current_user, limit: int = 10) -> list[dict[str, Any]]:
+    """Best-effort list of the user's most recently modified files.
+
+    Used to give the General assistant a sense of what the user has been
+    working on. Never raises: any failure yields an empty list.
+    """
+    try:
+        from backend.services.recent import list_recent
+
+        username = current_user.get("username") if isinstance(current_user, dict) else None
+        user_vaults = (
+            current_user.get("_token_vaults") or current_user.get("vaults", [])
+            if isinstance(current_user, dict)
+            else []
+        )
+        data = list_recent(username, user_vaults, limit=limit, mode="modified")
+        return list(data.get("files", []))
+    except Exception:  # pragma: no cover - defensive, prompt enrichment only
+        logger.debug("Could not gather recent files for assistant prompt", exc_info=True)
+        return []
+
+
 def _resolve_system_prompt(req, current_user) -> str:
     """Resolve the vault access and build the assistant system prompt.
 
@@ -179,11 +217,28 @@ def _resolve_system_prompt(req, current_user) -> str:
     effective_mode = context.get("scope", mode)
 
     if effective_mode == "general":
-        prompt = build_general_system_prompt(list(index.keys()))
+        prompt = build_general_system_prompt(
+            list(index.keys()),
+            app_context=_submitted_app_context(req),
+            recent_files=_recent_files_for_prompt(current_user),
+        )
     elif effective_mode == "documents":
         prompt = build_system_prompt(context, scope="documents")
     elif context["file_count"] == 0:
-        raise HTTPException(status_code=404, detail="Aucun fichier markdown trouvé dans ce dossier")
+        # Empty (or unreadable) directory: don't block the request. Answer as
+        # the General assistant would, telling the model the folder is empty so
+        # it can still help (create a file, explain the app, etc.).
+        prompt = build_general_system_prompt(
+            list(index.keys()),
+            app_context=_submitted_app_context(req),
+            recent_files=_recent_files_for_prompt(current_user),
+        )
+        prompt += (
+            f"\n## Dossier vide\nLe dossier « {req.directory or '/'} » "
+            f"(vault {req.vault}) ne contient aucun fichier markdown exploitable. "
+            "Réponds quand même à la demande de l'utilisateur sans contexte "
+            "documentaire, et propose une action de création si c'est pertinent.\n"
+        )
     else:
         prompt = build_system_prompt(context, scope="directory")