Handle invalid symbols (e.g. BF-B) gracefully in ORB detection

Daily bars chunk loop: on failure, retry symbol-by-symbol to isolate
and skip the bad ticker rather than crashing the entire detection.
Intraday bars chunk loop: catch and log failures, continue with rest.

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

apps/orb_trader/engine.py

@@ -105,7 +105,16 @@ class ORBTradingEngine:
         chunk_size = 200
         for i in range(0, len(tickers), chunk_size):
             chunk = tickers[i : i + chunk_size]
-            raw_bars.update(self._broker.get_bars(chunk, start, today))
+            try:
+                raw_bars.update(self._broker.get_bars(chunk, start, today))
+            except Exception as e:
+                self._log(f"  WARNING: daily bars chunk {i//chunk_size+1} failed ({e}) — skipping")
+                # Retry chunk symbol-by-symbol to isolate the bad ticker(s)
+                for sym in chunk:
+                    try:
+                        raw_bars.update(self._broker.get_bars([sym], start, today))
+                    except Exception:
+                        self._log(f"  Skipping invalid symbol: {sym}")
 
         daily_bars_dict = bars_to_enrichment_format(raw_bars)
 
@@ -137,13 +146,16 @@ class ORBTradingEngine:
         chunk_size = 100
         for i in range(0, len(tickers), chunk_size):
             chunk = tickers[i : i + chunk_size]
-            chunk_bars = self._broker.get_intraday_bars(
-                chunk,
-                start=market_open,
-                end=fetch_end,
-                timeframe_minutes=5,
-            )
-            intraday_raw.update(chunk_bars)
+            try:
+                chunk_bars = self._broker.get_intraday_bars(
+                    chunk,
+                    start=market_open,
+                    end=fetch_end,
+                    timeframe_minutes=5,
+                )
+                intraday_raw.update(chunk_bars)
+            except Exception as e:
+                self._log(f"  WARNING: intraday bars chunk {i//chunk_size+1} failed ({e}) — skipping")
 
         bars_by_ticker = intraday_bars_to_format(intraday_raw)
         self._log(