feat: Add request validation middleware to enforce security and data integrity checks on items_per_page limitation

src/middleware.py

@@ -158,11 +158,20 @@ class RequestValidationMiddleware(BaseHTTPMiddleware):
                 try:
                     size_val = int(value)
                     if size_val > 50:
-                        raise HTTPException(status_code=400, detail=f"Pagination size '{key}' cannot exceed 50")
+                        raise HTTPException(
+                            status_code=400,
+                            detail=f"Pagination size '{key}' cannot exceed 50",
+                        )
                     if size_val % 5 != 0:
-                        raise HTTPException(status_code=400, detail=f"Pagination size '{key}' must be a multiple of 5")
+                        raise HTTPException(
+                            status_code=400,
+                            detail=f"Pagination size '{key}' must be a multiple of 5",
+                        )
                 except ValueError:
-                    raise HTTPException(status_code=400, detail=f"Pagination size '{key}' must be an integer")
+                    raise HTTPException(
+                        status_code=400,
+                        detail=f"Pagination size '{key}' must be an integer",
+                    )
 
         # -------------------------
         # 4. Content-Type sanity