feat(hub): enrich AI coach with fund history, closed trades, and chat uploads

- Add 15-day fund snapshot store and /api/hub/account on all instances

- Summary includes yesterday/today trades, fund columns, and section 5 操作建议

- Chat context distinguishes empty positions from local monitors

- Support image/document attachments in AI chat

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

manual_trading_hub/hub_ai/store.py

@@ -163,7 +163,13 @@ def ensure_active_session(*, trading_day: str) -> dict:
     return create_new_session(trading_day=trading_day)
 
 
-def append_chat_message(session_id: str, role: str, content: str) -> dict:
+def append_chat_message(
+    session_id: str,
+    role: str,
+    content: str,
+    *,
+    attachments: Optional[list] = None,
+) -> dict:
     store = load_chat_store()
     sessions = store.get("sessions") or []
     target = None
@@ -174,6 +180,8 @@ def append_chat_message(session_id: str, role: str, content: str) -> dict:
     if not target:
         raise KeyError("session_not_found")
     msg = {"role": role, "content": content.strip(), "at": _now_str()}
+    if attachments:
+        msg["attachments"] = list(attachments)
     target.setdefault("messages", []).append(msg)
     target["updated_at"] = _now_str()
     if role == "user" and (target.get("title") in (None, "", "新对话")):