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

docker/nginx.conf

@@ -15,11 +15,23 @@ server {
         try_files $uri $uri/ /index.html;
     }
 
+    # ---------------------------------------------------------------------------
+    # Proxy /api/auth/* to the api-gateway /auth/* routes
+    # (Dashboard client uses baseURL=/api, so auth calls arrive as /api/auth/*)
+    # ---------------------------------------------------------------------------
+    location /api/auth/ {
+        proxy_pass http://api-gateway:8000/auth/;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+    }
+
     # ---------------------------------------------------------------------------
     # Proxy /api/* to the api-gateway service
     # ---------------------------------------------------------------------------
     location /api/ {
-        proxy_pass http://api-gateway:8000;
+        proxy_pass http://api-gateway:8000/api/;
         proxy_set_header Host $host;
         proxy_set_header X-Real-IP $remote_addr;
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;