feat(agent): align the document tools with the harness-trained shape — ls, read(path), grep(pattern, path?)

app/api/chat.py

@@ -49,27 +49,28 @@ outline (0 when absent) and the per-turn log line records
 
 Agent document tools (phase 37, PLAN §4 extension, owner permission
 2026-08-26; phase 45 removed the per-tool budgets — owner permission
-2026-08-27; phase 68 added the ``search_documents`` grep): a
+2026-08-27; phase 70 aligned the surface to the harness-trained
+``ls`` / ``read`` / ``grep`` — owner permission 2026-09-03): a
 **grounded** turn (``not plan.deflected``) no longer streams a bare
 ``chat_stream`` — it runs the agent loop (``app.rag.agent.run_agent``),
 which offers the model the three server-side tools
-``list_documents`` / ``read_document`` / ``search_documents`` for the
-whole turn (as many calls as the model wants, re-lists and re-searches
-included) until it answers or the round cap (``BOR_AGENT_MAX_ROUNDS``,
-default 10) forces one final no-tools answer. Each model-requested call
-streams as an SSE ``tool`` event — ``{"type": "tool", "name": …,
-"argument": "source/path" | pattern | null}`` — ahead of the answer's
-``delta`` frames: ``argument`` is the read document's path for
-``read_document``, the raw search pattern for ``search_documents``
-(a non-string pattern — a model error the backend refuses — yields
-null), and null for ``list_documents``. ``done.sources``,
-``query_log.sources`` and the per-turn log line all report the same
-combined source list (retrieval docs + the agent's read docs, deduped
-by ``(source, path)``, order preserved — a search adds no source; it is
-a locator, locked A5), and the log line records ``tool_calls=N`` after
-``thinking_chars=N`` (PLAN §9 line extension — ``N`` counts executed
-tool calls; rejected calls do not count). **Deflected turns keep the
-direct ``chat_stream`` — byte-identical to the pre-phase path (A8):**
+``ls`` / ``read`` / ``grep`` for the whole turn (as many calls as the
+model wants, re-lists and re-greps included) until it answers or the
+round cap (``BOR_AGENT_MAX_ROUNDS``, default 10) forces one final
+no-tools answer. Each model-requested call streams as an SSE ``tool``
+event — ``{"type": "tool", "name": …, "argument": … | null}`` — ahead
+of the answer's ``delta`` frames: ``argument`` is the single string the
+model passed — ``read``'s ``path`` (the combined ``source/path``),
+``grep``'s ``pattern``, ``ls``'s ``path`` — or null (a non-string
+value — a model error the backend refuses — and an omitted argument
+both yield null). ``done.sources``, ``query_log.sources`` and the
+per-turn log line all report the same combined source list (retrieval
+docs + the agent's read docs, deduped by ``(source, path)``, order
+preserved — a grep adds no source; it is a locator, locked A5), and the
+log line records ``tool_calls=N`` after ``thinking_chars=N`` (PLAN §9
+line extension — ``N`` counts executed tool calls; rejected calls do not
+count). **Deflected turns keep the direct ``chat_stream`` —
+byte-identical to the pre-phase path (A8):**
 the LOW prompt never carries tools, and with ``agent_max_rounds`` at
 **0** ``run_agent`` makes exactly one ``tools=None`` request,
 reproducing the pre-phase behavior (the kill switch).
@@ -400,21 +401,18 @@ async def chat(
             try:
                 async for piece in answer_stream:  # StreamPiece | ToolCallPiece | RetryPiece
                     if isinstance(piece, ToolCallPiece):
-                        # Phase 37 (PLAN §4 extension): one SSE ``tool``
-                        # frame per model-requested call. ``argument`` is
-                        # the read_document "source/path"; phase 68
-                        # extends it with the search_documents pattern
-                        # (a non-string pattern — a model error the
-                        # backend refuses — is null); null otherwise.
-                        if piece.name == "read_document":
-                            argument = (
-                                f"{piece.arguments.get('source')}/{piece.arguments.get('path')}"
-                            )
-                        elif piece.name == "search_documents":
-                            pattern = piece.arguments.get("pattern")
-                            argument = pattern if isinstance(pattern, str) else None
-                        else:
-                            argument = None
+                        # Phase 37 (PLAN §4 extension; phase 70): one SSE
+                        # ``tool`` frame per model-requested call.
+                        # ``argument`` is the single string the model
+                        # passed — ``read``'s ``path`` (the combined
+                        # ``source/path``), ``grep``'s ``pattern``,
+                        # ``ls``'s ``path`` — or null (a non-string value
+                        # is a model error the backend refuses, as is an
+                        # omitted argument).
+                        argument = piece.arguments.get(
+                            "pattern" if piece.name == "grep" else "path"
+                        )
+                        argument = argument if isinstance(argument, str) else None
                         yield sse_event(
                             ChatToolEvent(name=piece.name, argument=argument).model_dump()
                         )