Fix: Synchronous cache warming for accurate starters and PPG data

server.py

@@ -376,15 +376,17 @@ logger.info("Background scheduler started with jobs: update_elo (1h), sync_predi
 # =============================================================================
 def startup_cache_warming():
     """Warm all caches on startup for instant first requests."""
-    logger.info("Starting cache warming on startup...")
+    logger.info("Starting SYNCHRONOUS cache warming on startup...")
     try:
-        # Warm starter cache in background (takes ~5 seconds)
-        threading.Thread(target=warm_starter_cache, daemon=True).start()
-        logger.info("Starter cache warming initiated")
+        # Warm starter cache SYNCHRONOUSLY so data is ready before first request
+        # This ensures accurate, real NBA API data is shown immediately
+        warm_starter_cache()
+        logger.info("Starter cache warming COMPLETE - real data ready!")
     except Exception as e:
-        logger.warning(f"Startup cache warming error (non-critical): {e}")
+        logger.warning(f"Startup cache warming error: {e}")
+        logger.warning("Will use fallback data until next refresh")
 
-# Run startup warming
+# Run startup warming (blocks until complete for accurate data)
 startup_cache_warming()
 
 # =============================================================================