Remove and reorder unused imports across the project for cleaner and more consistent code structure

backend/app/main.py

@@ -4,13 +4,12 @@ from typing import Dict, Any
 
 from apscheduler.schedulers.asyncio import AsyncIOScheduler
 from fastapi import FastAPI, status, Request, HTTPException
+from fastapi.exceptions import RequestValidationError
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import HTMLResponse, JSONResponse
-from fastapi.exceptions import RequestValidationError
 from slowapi import Limiter, _rate_limit_exceeded_handler
-from slowapi.util import get_remote_address
 from slowapi.errors import RateLimitExceeded
-from sqlalchemy import text
+from slowapi.util import get_remote_address
 
 from app.api.main import api_router
 from app.core.config import settings