feat: Introduce Redis-backed stream services for enhanced job management

- Added createStreamServices function to configure job store and event transport, supporting both Redis and in-memory options.
- Updated GenerationJobManager to allow configuration with custom job stores and event transports, improving flexibility for different deployment scenarios.
- Refactored IJobStore interface to support asynchronous content retrieval, ensuring compatibility with Redis implementations.
- Implemented RedisEventTransport for real-time event delivery across instances, enhancing scalability and responsiveness.
- Updated InMemoryJobStore to align with new async patterns for content and run step retrieval, ensuring consistent behavior across storage options.

packages/api/src/stream/createStreamServices.ts

@@ -0,0 +1,130 @@
+import type { Redis, Cluster } from 'ioredis';
+import { logger } from '@librechat/data-schemas';
+import type { IJobStore, IEventTransport } from './interfaces/IJobStore';
+import { InMemoryJobStore } from './implementations/InMemoryJobStore';
+import { InMemoryEventTransport } from './implementations/InMemoryEventTransport';
+import { RedisJobStore } from './implementations/RedisJobStore';
+import { RedisEventTransport } from './implementations/RedisEventTransport';
+import { cacheConfig } from '~/cache/cacheConfig';
+import { ioredisClient } from '~/cache/redisClients';
+
+/**
+ * Configuration for stream services (optional overrides)
+ */
+export interface StreamServicesConfig {
+  /**
+   * Override Redis detection. If not provided, uses cacheConfig.USE_REDIS.
+   */
+  useRedis?: boolean;
+
+  /**
+   * Override Redis client. If not provided, uses ioredisClient from cache.
+   */
+  redisClient?: Redis | Cluster | null;
+
+  /**
+   * Dedicated Redis client for pub/sub subscribing.
+   * If not provided, will duplicate the main client.
+   */
+  redisSubscriber?: Redis | Cluster | null;
+
+  /**
+   * Options for in-memory job store
+   */
+  inMemoryOptions?: {
+    ttlAfterComplete?: number;
+    maxJobs?: number;
+  };
+}
+
+/**
+ * Stream services result
+ */
+export interface StreamServices {
+  jobStore: IJobStore;
+  eventTransport: IEventTransport;
+  isRedis: boolean;
+}
+
+/**
+ * Create stream services (job store + event transport).
+ *
+ * Automatically detects Redis from cacheConfig.USE_REDIS and uses
+ * the existing ioredisClient. Falls back to in-memory if Redis
+ * is not configured or not available.
+ *
+ * @example Auto-detect (uses cacheConfig)
+ * ```ts
+ * const services = createStreamServices();
+ * // Uses Redis if USE_REDIS=true, otherwise in-memory
+ * ```
+ *
+ * @example Force in-memory
+ * ```ts
+ * const services = createStreamServices({ useRedis: false });
+ * ```
+ */
+export function createStreamServices(config: StreamServicesConfig = {}): StreamServices {
+  // Use provided config or fall back to cache config
+  const useRedis = config.useRedis ?? cacheConfig.USE_REDIS;
+  const redisClient = config.redisClient ?? ioredisClient;
+  const { redisSubscriber, inMemoryOptions } = config;
+
+  // Check if we should and can use Redis
+  if (useRedis && redisClient) {
+    try {
+      // For subscribing, we need a dedicated connection
+      // If subscriber not provided, duplicate the main client
+      let subscriber = redisSubscriber;
+
+      if (!subscriber && 'duplicate' in redisClient) {
+        subscriber = (redisClient as Redis).duplicate();
+        logger.info('[StreamServices] Duplicated Redis client for subscriber');
+      }
+
+      if (!subscriber) {
+        logger.warn('[StreamServices] No subscriber client available, falling back to in-memory');
+        return createInMemoryServices(inMemoryOptions);
+      }
+
+      const jobStore = new RedisJobStore(redisClient);
+      const eventTransport = new RedisEventTransport(redisClient, subscriber);
+
+      logger.info('[StreamServices] Created Redis-backed stream services');
+
+      return {
+        jobStore,
+        eventTransport,
+        isRedis: true,
+      };
+    } catch (err) {
+      logger.error(
+        '[StreamServices] Failed to create Redis services, falling back to in-memory:',
+        err,
+      );
+      return createInMemoryServices(inMemoryOptions);
+    }
+  }
+
+  return createInMemoryServices(inMemoryOptions);
+}
+
+/**
+ * Create in-memory stream services
+ */
+function createInMemoryServices(options?: StreamServicesConfig['inMemoryOptions']): StreamServices {
+  const jobStore = new InMemoryJobStore({
+    ttlAfterComplete: options?.ttlAfterComplete ?? 300000, // 5 minutes
+    maxJobs: options?.maxJobs ?? 1000,
+  });
+
+  const eventTransport = new InMemoryEventTransport();
+
+  logger.info('[StreamServices] Created in-memory stream services');
+
+  return {
+    jobStore,
+    eventTransport,
+    isRedis: false,
+  };
+}