fix(agent): unambiguous document listing format for LLM parsing

app/rag/agent.py

@@ -26,7 +26,8 @@ task 04):
    path (the kill switch).
 2. Each tool call the model emits is executed server-side against
    Postgres only (no LLM, no network): ``list_documents`` returns the
-   indexed catalog — one ``source/path — title`` line per document,
+   indexed catalog — one ``source: X | path: Y | title: Z`` line per
+   document (phase 63: labeled fields — unambiguous for LLM parsing),
    ``GET /api/docs`` order (uncapped in v1; the UI never shows it, only
    the model does) — and ``read_document`` returns the document's **full**
    content (A7-revised contract: never truncated).
@@ -85,7 +86,7 @@ AGENT_TOOLS: list[dict[str, Any]] = [
             "name": "list_documents",
             "description": (
                 "List every document indexed in the knowledge base, one "
-                "`source/path — title` line each"
+                "`source: X | path: Y | title: Z` line each"
             ),
             "parameters": {"type": "object", "properties": {}, "required": []},
         },
@@ -104,15 +105,17 @@ AGENT_TOOLS: list[dict[str, Any]] = [
                     "source": {
                         "type": "string",
                         "description": (
-                            "The document's source (a directory basename, "
-                            "e.g. 'Homelab')."
+                            "The document's source, as shown after 'source: ' in the "
+                            "list_documents output (e.g. 'Homelab' from "
+                            "'source: Homelab | path: homelab/aws-route53.md')."
                         ),
                     },
                     "path": {
                         "type": "string",
                         "description": (
-                            "The document's path relative to its source "
-                            "directory."
+                            "The document's path, as shown after 'path: ' in the "
+                            "list_documents output (e.g. 'homelab/aws-route53.md' from "
+                            "'source: Homelab | path: homelab/aws-route53.md')."
                         ),
                     },
                 },
@@ -186,7 +189,8 @@ def _execute_tool(
     if call.name == "list_documents":
         rows = list_catalog(db)
         listing = f"{len(rows)} documents:\n" + "\n".join(
-            f"{source}/{path} — {title}" for source, path, title in rows
+            f"source: {source} | path: {path} | title: {title}"
+            for source, path, title in rows
         )
         holder.tool_calls += 1
         return listing