feat(middleware): add process time header middleware for request timing

main.py

@@ -1,4 +1,4 @@
-from fastapi import FastAPI
+from fastapi import FastAPI, Request
 from fastapi.middleware.cors import CORSMiddleware
 from contextlib import asynccontextmanager
 
@@ -7,6 +7,8 @@ from api.routers import memory
 from db.session import create_db_and_tables
 from core.config import get_settings
 
+import time
+
 settings = get_settings()
 
 @asynccontextmanager
@@ -25,7 +27,17 @@ app = FastAPI(
     lifespan=lifespan
 )
 
-# --- Middleware ---
+# --- Middlewares ---
+
+@app.middleware("http")
+async def add_process_time_header(request: Request, call_next):
+    start_time = time.time()
+    response = await call_next(request)
+    process_time = time.time() - start_time
+    response.headers["X-Process-Time"] = str(process_time)
+    print(f"INFO:     Request {request.method} {request.url.path} processed in {process_time:.4f} sec")
+    return response
+
 app.add_middleware(
     CORSMiddleware,
     allow_origins=[settings.FRONTEND_URL, "http://127.0.0.1:3000"],