added duplicate check and database

app/database.py

@@ -1,14 +1,19 @@
+# app/database.py
 #!/usr/bin/env python3
 
-from sqlalchemy import create_engine, Column, String, Integer
+from sqlalchemy import create_engine
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import sessionmaker
-from .config import settings
+from app.config import settings
 
 Base = declarative_base()
 engine = create_engine(settings.database_url, connect_args={"check_same_thread": False})
 SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
 
+def init_db():
+    """Call this once (e.g. on startup) to create tables if they don't exist."""
+    Base.metadata.create_all(bind=engine)
+
 def get_db():
     db = SessionLocal()
     try: