feat: scene close on hard signals with manual override

chat/web/drawer.py

@@ -135,6 +135,46 @@ async def drawer(chat_id: str, request: Request, conn=Depends(get_conn)):
 #      HTMX swaps into ``#drawer``.
 
 
+@router.post(
+    "/chats/{chat_id}/drawer/scene/close",
+    response_class=HTMLResponse,
+)
+async def close_scene_manual(
+    chat_id: str,
+    request: Request,
+    conn=Depends(get_conn),
+):
+    """Manual scene close from the drawer button.
+
+    Always available when there's an active scene; mirrors the auto-close
+    path in the turn flow but bypasses the classifier. Returns the refreshed
+    drawer partial so HTMX swaps it in. ``400`` when no scene is active —
+    the button is hidden in that state but a stale tab might still POST.
+    """
+    chat = get_chat(conn, chat_id)
+    if chat is None:
+        raise HTTPException(status_code=404, detail=f"chat not found: {chat_id}")
+
+    scene = active_scene(conn, chat_id)
+    if scene is None:
+        raise HTTPException(
+            status_code=400, detail="no active scene to close"
+        )
+
+    append_and_apply(
+        conn,
+        kind="scene_closed",
+        payload={
+            "scene_id": scene["id"],
+            "ended_at": chat.get("time"),
+            # T27 will set this from the per-POV summary pass; for T26 we
+            # default to 0 so the projector update has a value to write.
+            "significance": 0,
+        },
+    )
+    return await drawer(chat_id, request, conn)
+
+
 @router.post(
     "/chats/{chat_id}/drawer/edge/{source_id}/{target_id}/affinity",
     response_class=HTMLResponse,