fix: single worker + graceful table creation for Neon

backend/app/main.py

@@ -31,26 +31,29 @@ async def lifespan(app: FastAPI):
     logger.info("Starting %s v%s", settings.app_name, settings.app_version)
 
     # Create database tables
-    async with engine.begin() as conn:
-        from app.models import (  # noqa: F401 — force model registration
-            Asset,
-            BacktestResult,
-            Exchange,
-            Factor,
-            FactorExposure,
-            FeatureData,
-            Holding,
-            MarketplaceEntry,
-            NewsArticle,
-            Portfolio,
-            PriceData,
-            ResearchReport,
-            Signal,
-            Strategy,
-            User,
-        )
-        await conn.run_sync(Base.metadata.create_all)
-        logger.info("Database tables created successfully")
+    try:
+        async with engine.begin() as conn:
+            from app.models import (  # noqa: F401 — force model registration
+                Asset,
+                BacktestResult,
+                Exchange,
+                Factor,
+                FactorExposure,
+                FeatureData,
+                Holding,
+                MarketplaceEntry,
+                NewsArticle,
+                Portfolio,
+                PriceData,
+                ResearchReport,
+                Signal,
+                Strategy,
+                User,
+            )
+            await conn.run_sync(Base.metadata.create_all)
+            logger.info("Database tables created successfully")
+    except Exception as e:
+        logger.warning("Table creation skipped (tables may already exist): %s", e)
 
     # Seed exchange data
     await _seed_exchanges()

supervisord.conf

@@ -15,7 +15,7 @@ stderr_logfile=/dev/stderr
 stderr_logfile_maxbytes=0
 
 [program:uvicorn]
-command=uvicorn app.main:app --host 127.0.0.1 --port 8000 --workers 2 --timeout-keep-alive 120
+command=uvicorn app.main:app --host 127.0.0.1 --port 8000 --workers 1 --timeout-keep-alive 120
 directory=/app
 autostart=true
 autorestart=true