fix(agent): guide generated media into workspace out

tests/test_context_prompt_cache.py

@@ -2,10 +2,10 @@
 
 from __future__ import annotations
 
+import datetime as datetime_module
 from datetime import datetime as real_datetime
 from importlib.resources import files as pkg_files
 from pathlib import Path
-import datetime as datetime_module
 
 from nanobot.agent.context import ContextBuilder
 
@@ -47,6 +47,16 @@ def test_system_prompt_stays_stable_when_clock_changes(tmp_path, monkeypatch) ->
     assert prompt1 == prompt2
 
 
+def test_system_prompt_mentions_workspace_out_for_generated_artifacts(tmp_path) -> None:
+    workspace = _make_workspace(tmp_path)
+    builder = ContextBuilder(workspace)
+
+    prompt = builder.build_system_prompt()
+
+    assert f"Put generated artifacts meant for delivery to the user under: {workspace}/out" in prompt
+    assert f"For QQ delivery, local images under `{workspace}/out` can be auto-published" in prompt
+
+
 def test_runtime_context_is_separate_untrusted_user_message(tmp_path) -> None:
     """Runtime metadata should be merged with the user message."""
     workspace = _make_workspace(tmp_path)