refactor: Centralize database session management in a shared dependency module

routes/maintenance.py

@@ -5,21 +5,13 @@ from fastapi import APIRouter, Depends, HTTPException, status
 from pydantic import BaseModel, ConfigDict, PositiveFloat
 from sqlalchemy.orm import Session
 
-from config.database import SessionLocal
 from models.maintenance import Maintenance
+from routes.dependencies import get_db
 
 
 router = APIRouter(prefix="/api/maintenance", tags=["Maintenance"])
 
 
-def get_db():
-    db = SessionLocal()
-    try:
-        yield db
-    finally:
-        db.close()
-
-
 class MaintenanceBase(BaseModel):
     equipment_id: int
     scenario_id: int