🔄 refactor: MCP Registry System with Distributed Caching (#10191)

* refactor: Restructure MCP registry system with caching

- Split MCPServersRegistry into modular components:
  - MCPServerInspector: handles server inspection and health checks
  - MCPServersInitializer: manages server initialization logic
  - MCPServersRegistry: simplified registry coordination
- Add distributed caching layer:
  - ServerConfigsCacheRedis: Redis-backed configuration cache
  - ServerConfigsCacheInMemory: in-memory fallback cache
  - RegistryStatusCache: distributed leader election state
- Add promise utilities (withTimeout) replacing Promise.race patterns
- Add comprehensive cache integration tests for all cache implementations
- Remove unused MCPManager.getAllToolFunctions method

* fix: Update OAuth flow to include user-specific headers

* chore: Update Jest configuration to ignore additional test files

- Added patterns to ignore files ending with .helper.ts and .helper.d.ts in testPathIgnorePatterns for cleaner test runs.

* fix: oauth headers in callback

* chore: Update Jest testPathIgnorePatterns to exclude helper files

- Modified testPathIgnorePatterns in package.json to ignore files ending with .helper.ts and .helper.d.ts for cleaner test execution.

* ci: update test mocks

---------

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

api/server/routes/mcp.js

@@ -6,6 +6,7 @@ const {
   MCPOAuthHandler,
   MCPTokenStorage,
   getUserMCPAuthMap,
+  mcpServersRegistry,
 } = require('@librechat/api');
 const { getMCPManager, getFlowStateManager, getOAuthReconnectionManager } = require('~/config');
 const { getMCPSetupData, getServerConnectionStatus } = require('~/server/services/MCP');
@@ -61,11 +62,12 @@ router.get('/:serverName/oauth/initiate', requireJwtAuth, async (req, res) => {
       return res.status(400).json({ error: 'Invalid flow state' });
     }
 
+    const oauthHeaders = await getOAuthHeaders(serverName, userId);
     const { authorizationUrl, flowId: oauthFlowId } = await MCPOAuthHandler.initiateOAuthFlow(
       serverName,
       serverUrl,
       userId,
-      getOAuthHeaders(serverName),
+      oauthHeaders,
       oauthConfig,
     );
 
@@ -133,12 +135,8 @@ router.get('/:serverName/oauth/callback', async (req, res) => {
     });
 
     logger.debug('[MCP OAuth] Completing OAuth flow');
-    const tokens = await MCPOAuthHandler.completeOAuthFlow(
-      flowId,
-      code,
-      flowManager,
-      getOAuthHeaders(serverName),
-    );
+    const oauthHeaders = await getOAuthHeaders(serverName, flowState.userId);
+    const tokens = await MCPOAuthHandler.completeOAuthFlow(flowId, code, flowManager, oauthHeaders);
     logger.info('[MCP OAuth] OAuth flow completed, tokens received in callback route');
 
     /** Persist tokens immediately so reconnection uses fresh credentials */
@@ -356,7 +354,7 @@ router.post('/:serverName/reinitialize', requireJwtAuth, async (req, res) => {
     logger.info(`[MCP Reinitialize] Reinitializing server: ${serverName}`);
 
     const mcpManager = getMCPManager();
-    const serverConfig = mcpManager.getRawConfig(serverName);
+    const serverConfig = await mcpServersRegistry.getServerConfig(serverName, user.id);
     if (!serverConfig) {
       return res.status(404).json({
         error: `MCP server '${serverName}' not found in configuration`,
@@ -505,8 +503,7 @@ router.get('/:serverName/auth-values', requireJwtAuth, async (req, res) => {
       return res.status(401).json({ error: 'User not authenticated' });
     }
 
-    const mcpManager = getMCPManager();
-    const serverConfig = mcpManager.getRawConfig(serverName);
+    const serverConfig = await mcpServersRegistry.getServerConfig(serverName, user.id);
     if (!serverConfig) {
       return res.status(404).json({
         error: `MCP server '${serverName}' not found in configuration`,
@@ -545,9 +542,8 @@ router.get('/:serverName/auth-values', requireJwtAuth, async (req, res) => {
   }
 });
 
-function getOAuthHeaders(serverName) {
-  const mcpManager = getMCPManager();
-  const serverConfig = mcpManager.getRawConfig(serverName);
+async function getOAuthHeaders(serverName, userId) {
+  const serverConfig = await mcpServersRegistry.getServerConfig(serverName, userId);
   return serverConfig?.oauth_headers ?? {};
 }