🔄 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/cache/cacheConfig.ts

@@ -0,0 +1,89 @@
+import { readFileSync, existsSync } from 'fs';
+import { logger } from '@librechat/data-schemas';
+import { CacheKeys } from 'librechat-data-provider';
+import { math, isEnabled } from '~/utils';
+
+// To ensure that different deployments do not interfere with each other's cache, we use a prefix for the Redis keys.
+// This prefix is usually the deployment ID, which is often passed to the container or pod as an env var.
+// Set REDIS_KEY_PREFIX_VAR to the env var that contains the deployment ID.
+const REDIS_KEY_PREFIX_VAR = process.env.REDIS_KEY_PREFIX_VAR;
+const REDIS_KEY_PREFIX = process.env.REDIS_KEY_PREFIX;
+if (REDIS_KEY_PREFIX_VAR && REDIS_KEY_PREFIX) {
+  throw new Error('Only either REDIS_KEY_PREFIX_VAR or REDIS_KEY_PREFIX can be set.');
+}
+
+const USE_REDIS = isEnabled(process.env.USE_REDIS);
+if (USE_REDIS && !process.env.REDIS_URI) {
+  throw new Error('USE_REDIS is enabled but REDIS_URI is not set.');
+}
+
+// Comma-separated list of cache namespaces that should be forced to use in-memory storage
+// even when Redis is enabled. This allows selective performance optimization for specific caches.
+const FORCED_IN_MEMORY_CACHE_NAMESPACES = process.env.FORCED_IN_MEMORY_CACHE_NAMESPACES
+  ? process.env.FORCED_IN_MEMORY_CACHE_NAMESPACES.split(',').map((key) => key.trim())
+  : [];
+
+// Validate against CacheKeys enum
+if (FORCED_IN_MEMORY_CACHE_NAMESPACES.length > 0) {
+  const validKeys = Object.values(CacheKeys) as string[];
+  const invalidKeys = FORCED_IN_MEMORY_CACHE_NAMESPACES.filter((key) => !validKeys.includes(key));
+
+  if (invalidKeys.length > 0) {
+    throw new Error(
+      `Invalid cache keys in FORCED_IN_MEMORY_CACHE_NAMESPACES: ${invalidKeys.join(', ')}. Valid keys: ${validKeys.join(', ')}`,
+    );
+  }
+}
+
+/** Helper function to safely read Redis CA certificate from file
+ * @returns {string|null} The contents of the CA certificate file, or null if not set or on error
+ */
+const getRedisCA = (): string | null => {
+  const caPath = process.env.REDIS_CA;
+  if (!caPath) {
+    return null;
+  }
+
+  try {
+    if (existsSync(caPath)) {
+      return readFileSync(caPath, 'utf8');
+    } else {
+      logger.warn(`Redis CA certificate file not found: ${caPath}`);
+      return null;
+    }
+  } catch (error) {
+    logger.error(`Failed to read Redis CA certificate file '${caPath}':`, error);
+    return null;
+  }
+};
+
+const cacheConfig = {
+  FORCED_IN_MEMORY_CACHE_NAMESPACES,
+  USE_REDIS,
+  REDIS_URI: process.env.REDIS_URI,
+  REDIS_USERNAME: process.env.REDIS_USERNAME,
+  REDIS_PASSWORD: process.env.REDIS_PASSWORD,
+  REDIS_CA: getRedisCA(),
+  REDIS_KEY_PREFIX: process.env[REDIS_KEY_PREFIX_VAR ?? ''] || REDIS_KEY_PREFIX || '',
+  REDIS_MAX_LISTENERS: math(process.env.REDIS_MAX_LISTENERS, 40),
+  REDIS_PING_INTERVAL: math(process.env.REDIS_PING_INTERVAL, 0),
+  /** Max delay between reconnection attempts in ms */
+  REDIS_RETRY_MAX_DELAY: math(process.env.REDIS_RETRY_MAX_DELAY, 3000),
+  /** Max number of reconnection attempts (0 = infinite) */
+  REDIS_RETRY_MAX_ATTEMPTS: math(process.env.REDIS_RETRY_MAX_ATTEMPTS, 10),
+  /** Connection timeout in ms */
+  REDIS_CONNECT_TIMEOUT: math(process.env.REDIS_CONNECT_TIMEOUT, 10000),
+  /** Queue commands when disconnected */
+  REDIS_ENABLE_OFFLINE_QUEUE: isEnabled(process.env.REDIS_ENABLE_OFFLINE_QUEUE ?? 'true'),
+  /** flag to modify redis connection by adding dnsLookup this is required when connecting to elasticache for ioredis
+   * see "Special Note: Aws Elasticache Clusters with TLS" on this webpage:  https://www.npmjs.com/package/ioredis **/
+  REDIS_USE_ALTERNATIVE_DNS_LOOKUP: isEnabled(process.env.REDIS_USE_ALTERNATIVE_DNS_LOOKUP),
+  /** Enable redis cluster without the need of multiple URIs */
+  USE_REDIS_CLUSTER: isEnabled(process.env.USE_REDIS_CLUSTER ?? 'false'),
+  CI: isEnabled(process.env.CI),
+  DEBUG_MEMORY_CACHE: isEnabled(process.env.DEBUG_MEMORY_CACHE),
+
+  BAN_DURATION: math(process.env.BAN_DURATION, 7200000), // 2 hours
+};
+
+export { cacheConfig };