feat: productionize local service — fix signal pipeline, lower thresholds, add company-name ticker extraction

- Point Ollama to local instance via host.docker.internal, use gemma3 model
- Remove Docker Ollama service (using host's Ollama instead)
- Add company-name-to-ticker mapping (Apple→AAPL, Tesla→TSLA, etc.) for RSS articles
- Lower signal thresholds for faster feedback with paper trading:
  - FinBERT confidence: 0.6→0.4, signal strength: 0.3→0.15
  - News strategy: article_count 2→1, confidence 0.5→0.3, score ±0.3→±0.15
- Fix market data BarSet access bug (BarSet.__contains__ returns False incorrectly)
- Fix market data SIP feed error by switching to IEX feed for free Alpaca accounts
- Fix nginx proxy routing for /api/auth/* to api-gateway /auth/*
- Add seed_sample_data script
- Update tests for new thresholds and alpaca mock modules

tests/services/test_api_routes.py

@@ -188,9 +188,10 @@ class TestTradesListEndpoint:
         trade.signal_id = None
         trade.created_at = datetime(2024, 1, 1, tzinfo=timezone.utc)
 
-        # session.execute will be called twice: count + data
+        # session.execute is called twice: count + data (now returns tuples)
         count_result = _make_execute_result([], scalar=1)
-        data_result = _make_execute_result([trade])
+        data_result = MagicMock()
+        data_result.all.return_value = [(trade, None)]  # (Trade, strategy_name)
         session.execute = AsyncMock(side_effect=[count_result, data_result])
 
         resp = client.get("/api/trades")
@@ -242,8 +243,11 @@ class TestStrategiesEndpoint:
         strategy.active = True
         strategy.created_at = datetime(2024, 1, 1, tzinfo=timezone.utc)
 
+        # First call: list strategies; subsequent calls: trades per strategy
+        strategies_result = _make_execute_result([strategy])
+        trades_result = _make_execute_result([])  # no trades
         session.execute = AsyncMock(
-            return_value=_make_execute_result([strategy])
+            side_effect=[strategies_result, trades_result]
         )
 
         resp = client.get("/api/strategies")