feat: scene close on hard signals with manual override

tests/test_memory_write.py

@@ -156,6 +156,12 @@ def client(tmp_path, monkeypatch):
     canned_state_update = json.dumps(
         {"affinity_delta": 0, "trust_delta": 0, "knowledge_facts": []}
     )
+    # T26 scene-close detection runs after the state-update pass. ``_seed_full``
+    # below doesn't open a scene so the classifier call is short-circuited in
+    # turns.py — but the canned slot stays in place to document the order.
+    canned_scene_close = json.dumps(
+        {"should_close": False, "reason": "no signal"}
+    )
 
     from chat.web.kickoff import get_llm_client
 
@@ -165,6 +171,7 @@ def client(tmp_path, monkeypatch):
             canned_response,
             canned_state_update,
             canned_state_update,
+            canned_scene_close,
         ]
     )
     app.dependency_overrides[get_llm_client] = lambda: mock