feat: initial postcard manager - FastAPI + Jinja2 + SQLite

app/database.py

@@ -0,0 +1,25 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker, DeclarativeBase
+
+from app.config import DATABASE_URL
+
+engine = create_engine(DATABASE_URL, connect_args={"check_same_thread": False})
+SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False)
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+
+def init_db():
+    from app import models  # noqa: F401
+
+    Base.metadata.create_all(bind=engine)