feat: update dependencies and add dotenv, express-rate-limit, and zod; enhance adminSchemas validation

backend/src/validators/adminSchemas.ts

@@ -11,7 +11,7 @@ export const updateSettingSchema = z.object({
 })
 
 export const listUsersQuerySchema = z.object({
-  page: z.string().regex(/^\d+$/).optional().transform(v => (v ? Number(v) : 1)),
+  page: z.string().regex(/^\d+$/).optional().transform((v: string | undefined) => (v ? Number(v) : 1)),
   search: z.string().optional(),
 })