feat(hub): rolling chat summary to cap AI context and prevent mid-session failures

Co-authored-by: Cursor <cursoragent@cursor.com>

manual_trading_hub/hub_ai/store.py

@@ -165,6 +165,7 @@ def create_new_session(
         "created_at": _now_str(),
         "updated_at": _now_str(),
         "messages": [],
+        "rolling_summary": "",
     }
     store.setdefault("sessions", []).append(session)
     store["active_session_id"] = session["id"]
@@ -179,6 +180,22 @@ def ensure_active_session(*, trading_day: str) -> dict:
     return create_new_session(trading_day=trading_day)
 
 
+def update_session_rolling_summary(session_id: str, summary: str) -> dict:
+    store = load_chat_store()
+    target = None
+    for s in store.get("sessions") or []:
+        if str(s.get("id")) == str(session_id):
+            target = s
+            break
+    if not target:
+        raise KeyError("session_not_found")
+    target["rolling_summary"] = str(summary or "").strip()
+    target["updated_at"] = _now_str()
+    store["active_session_id"] = target["id"]
+    save_chat_store(store)
+    return target
+
+
 def append_chat_message(
     session_id: str,
     role: str,