Refactor database sessions into FastAPI dependency

dependencies.py

@@ -0,0 +1,17 @@
+from typing import Annotated
+
+from fastapi import Depends
+from sqlalchemy.orm import Session
+
+from database import engine
+
+
+def get_session():
+    with Session(engine, expire_on_commit=False) as session:
+        yield session
+
+
+SessionDep = Annotated[
+    Session,
+    Depends(get_session),
+]