🔄 refactor: Migrate Cache Logic to TypeScript (#9771)

* Refactor: Moved Redis cache infra logic into `packages/api`
- Moved cacheFactory and redisClients from `api/cache` into `packages/api/src/cache` so that features in `packages/api` can use cache without importing backward from the backend.
- Converted all moved files into TS with proper typing.
- Created integration tests to run against actual Redis servers for redisClients and cacheFactory.
- Added a GitHub workflow to run integration tests for the cache feature.
- Bug fix: keyvRedisClient now implements the PING feature properly.

* chore: consolidate imports in getLogStores.js

* chore: reorder imports

* chore: re-add fs-extra as dev dep.

* chore: reorder imports in cacheConfig.ts, cacheFactory.ts, and keyvMongo.ts

---------

Co-authored-by: Danny Avila <danny@librechat.ai>

packages/api/src/utils/math.ts

@@ -12,8 +12,8 @@
  *
  * @throws Throws an error if the input is not a string or number, contains invalid characters, or does not evaluate to a number.
  */
-export function math(str: string | number, fallbackValue?: number): number {
-  const fallback = typeof fallbackValue !== 'undefined' && typeof fallbackValue === 'number';
+export function math(str: string | number | undefined, fallbackValue?: number): number {
+  const fallback = fallbackValue != null;
   if (typeof str !== 'string' && typeof str === 'number') {
     return str;
   } else if (typeof str !== 'string') {