Isolate CTP in worker process and improve strategy roll UX.

Split vn.py into qihuo-ctp worker with IPC client bridge, keep CTP connected during breaks with cached account fallback, speed up strategy page loads, and allow off-session breakout roll submissions.

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

trading_context.py

@@ -79,8 +79,47 @@ def get_pending_order_timeout_sec(get_setting: Callable[[str, str], str]) -> int
     return get_pending_order_timeout_min(get_setting) * 60
 
 
+def _cached_ctp_account(mode: str) -> dict[str, float]:
+    """CTP 未连接时，用最近一次 worker/持仓快照里的账户权益。"""
+    import json
+
+    try:
+        from position_stream import position_hub
+
+        snap = position_hub.get_snapshot() or {}
+        cap = float(snap.get("capital") or 0)
+        if cap > 0:
+            return {"balance": cap}
+    except Exception:
+        pass
+    try:
+        from db_conn import connect_db
+
+        conn = connect_db()
+        try:
+            row = conn.execute(
+                "SELECT value FROM ctp_worker_snapshots WHERE key='account' LIMIT 1"
+            ).fetchone()
+        finally:
+            conn.close()
+        if row and row["value"]:
+            acc = json.loads(row["value"])
+            balance = float(acc.get("balance") or 0)
+            available = acc.get("available")
+            out: dict[str, float] = {}
+            if balance > 0:
+                out["balance"] = balance
+            if available is not None:
+                out["available"] = float(available)
+            return out
+    except Exception:
+        pass
+    del mode
+    return {}
+
+
 def get_account_capital(conn, get_setting: Callable[[str, str], str]) -> float:
-    """优先 SimNow/期货公司 CTP 权益；未连接时用设置中的参考资金。"""
+    """优先 SimNow/期货公司 CTP 权益；未连接时用最近快照或设置中的参考资金。"""
     del conn
     mode = get_trading_mode(get_setting)
     try:
@@ -93,6 +132,10 @@ def get_account_capital(conn, get_setting: Callable[[str, str], str]) -> float:
                 return float(bal)
     except Exception:
         pass
+    cached = _cached_ctp_account(mode)
+    balance = float(cached.get("balance") or 0)
+    if balance > 0:
+        return balance
     try:
         return float(get_setting("live_capital", "0") or 0)
     except (TypeError, ValueError):