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.

api/server/index.js

@@ -17,6 +17,7 @@ const {
   handleJsonParseError,
   initializeFileStorage,
   GenerationJobManager,
+  createStreamServices,
 } = require('@librechat/api');
 const { connectDb, indexSync } = require('~/db');
 const initializeOAuthReconnectManager = require('./services/initializeOAuthReconnectManager');
@@ -193,6 +194,10 @@ const startServer = async () => {
     await initializeMCPs();
     await initializeOAuthReconnectManager();
     await checkMigrations();
+
+    // Configure stream services (auto-detects Redis from USE_REDIS env var)
+    const streamServices = createStreamServices();
+    GenerationJobManager.configure(streamServices);
     GenerationJobManager.initialize();
   });
 };