refactor(V2): IBKR final review fixes — WS shutdown, conid match, clock note

Final code-review fixes:
- __main__: lifespan stops IBKRWebSocket singletons before registry close
- close_position: resolve symbol→conid first, match positions on conid
  (was matching contractDesc which is a long display string, not ticker)
- close_all_positions: prefer ticker field, fallback to contractDesc
- get_clock: explicit approximate=true + note about US holidays/half-days

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/cerbero_mcp/__main__.py

@@ -9,6 +9,7 @@ Boot:
 """
 from __future__ import annotations
 
+import contextlib
 from contextlib import asynccontextmanager
 from typing import Literal, cast
 
@@ -54,6 +55,11 @@ def _make_app(settings: Settings) -> FastAPI:
         try:
             yield
         finally:
+            # Stop any IBKR WebSocket singletons before closing client registry
+            ibkr_ws_dict = getattr(app.state, "ibkr_ws", {}) or {}
+            for ws in ibkr_ws_dict.values():
+                with contextlib.suppress(Exception):
+                    await ws.stop()
             await app.state.registry.aclose()
 
     app.router.lifespan_context = lifespan

src/cerbero_mcp/exchanges/ibkr/client.py

@@ -392,10 +392,17 @@ class IBKRClient:
     async def close_position(
         self, symbol: str, qty: float | None = None
     ) -> dict:
+        # Resolve symbol → conid, then match positions on conid (positions
+        # return `contractDesc` as a long display string, not ticker).
+        sec_type = _SEC_TYPE_MAP.get("stocks", "STK")
+        conid = await self.resolve_conid(symbol, sec_type)
         positions = await self.get_positions()
-        target = next((p for p in positions if p.get("contractDesc") == symbol), None)
+        target = next(
+            (p for p in positions if int(p.get("conid", 0)) == conid),
+            None,
+        )
         if not target:
-            raise IBKRError(f"IBKR_NO_POSITION: {symbol}")
+            raise IBKRError(f"IBKR_NO_POSITION: {symbol} (conid={conid})")
         position_qty = float(target.get("position", 0))
         close_qty = abs(qty if qty is not None else position_qty)
         side = "SELL" if position_qty > 0 else "BUY"
@@ -407,7 +414,7 @@ class IBKRClient:
         positions = await self.get_positions()
         results = []
         for p in positions:
-            sym = p.get("contractDesc")
+            sym = p.get("ticker") or p.get("contractDesc")
             if not sym:
                 continue
             try:

src/cerbero_mcp/exchanges/ibkr/tools.py

@@ -192,6 +192,12 @@ async def get_clock(client: IBKRClient, params: GetClockReq) -> dict:
         "timestamp": now.isoformat(),
         "is_open": _dt.time(13, 30) <= now.time() <= _dt.time(20, 0)
                    and now.weekday() < 5,
+        "approximate": True,
+        "note": (
+            "is_open is a UTC-based approximation; does not account for "
+            "US market holidays or half-days. Use IBKR /trsrv/marketdata/calendar "
+            "for authoritative schedule."
+        ),
     }