fix: show JUNIORBEES.NS position in paper MTM by fetching unknown LTP

market.py's LTP cache only has NIFTYBEES.NS and GOLDBEES.NS. For Alpha
Shield, JUNIORBEES.NS was missing from the map so paper_mtm.py was
silently dropping it. Now falls back to fetch_live_price for any symbol
not in the cached map.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/paper_mtm.py

@@ -12,6 +12,7 @@ if str(PROJECT_ROOT) not in sys.path:
     sys.path.append(str(PROJECT_ROOT))
 
 from indian_paper_trading_strategy.engine.db import engine_context
+from indian_paper_trading_strategy.engine.data import fetch_live_price
 from market import get_ltp
 
 from indian_paper_trading_strategy.engine.state import load_state
@@ -45,7 +46,10 @@ def paper_mtm(request: Request) -> Dict[str, Any]:
         avg_price = float(pos.get("avg_price", 0))
         ltp = ltp_map.get(symbol)
         if ltp is None:
-            continue
+            try:
+                ltp = fetch_live_price(symbol, allow_cache=True)
+            except Exception:
+                ltp = float(pos.get("last_price") or pos.get("avg_price") or 0)
 
         pnl = (ltp - avg_price) * qty
         positions_value += qty * ltp