🔄 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>

packages/api/jest.config.mjs

@@ -1,7 +1,13 @@
 export default {
   collectCoverageFrom: ['src/**/*.{js,jsx,ts,tsx}', '!<rootDir>/node_modules/'],
   coveragePathIgnorePatterns: ['/node_modules/', '/dist/'],
-  testPathIgnorePatterns: ['/node_modules/', '/dist/', '\\.dev\\.ts$'],
+  testPathIgnorePatterns: [
+    '/node_modules/',
+    '/dist/',
+    '\\.dev\\.ts$',
+    '\\.helper\\.ts$',
+    '\\.helper\\.d\\.ts$',
+  ],
   coverageReporters: ['text', 'cobertura'],
   testResultsProcessor: 'jest-junit',
   moduleNameMapper: {
@@ -18,4 +24,4 @@ export default {
   // },
   restoreMocks: true,
   testTimeout: 15000,
-};
+};