Implement database migration

backend/app.py

@@ -1,5 +1,7 @@
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
+from migration import run_auto_migration
+from db import engine
 
 from routes import account, messaging, profile, push
 
@@ -19,4 +21,13 @@ app.add_middleware(
 app.include_router(account.router)
 app.include_router(messaging.router)
 app.include_router(profile.router)
-app.include_router(push.router, prefix="/push")
+app.include_router(push.router, prefix="/push")
+
+
+@app.on_event("startup")
+def _auto_migrate_on_startup():
+    try:
+        run_auto_migration(engine)
+    except Exception:
+        # Keep startup resilient; errors should be visible in server logs
+        pass