fix: add sqlalchemy connection pool recycling to prevent EOF drops

Author: whynotkimhari

src/backend/db/base.py

@@ -38,7 +38,12 @@ def get_fernet():
 DATABASE_URL = os.getenv("DATABASE_URL")
 
 # Create Engine
-engine = create_engine(DATABASE_URL, echo=False)
+engine = create_engine(
+    DATABASE_URL,
+    echo=False,
+    pool_pre_ping=True,  # Test connection liveness upon checkout
+    pool_recycle=300,    # Recycle connections older than 5 minutes to prevent EOF drops by proxy/DB
+)
 
 # Session Factory
 SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)