🤖 feat: Agent Handoffs (Routing) (#10176)

* feat: Add support for agent handoffs with edges in agent forms and schemas

chore: Mark `agent_ids` field as deprecated in favor of edges across various schemas and types

chore: Update dependencies for @langchain/core and @librechat/agents to latest versions

chore: Update peer dependency for @librechat/agents to version 3.0.0-rc2 in package.json

chore: Update @librechat/agents dependency to version 3.0.0-rc3 in package.json and package-lock.json

feat: first pass, multi-agent handoffs

fix: update output type to ToolMessage in memory handling functions

fix: improve type checking for graphConfig in createRun function

refactor: remove unused content filtering logic in AgentClient

chore: update @librechat/agents dependency to version 3.0.0-rc4 in package.json and package-lock.json

fix: update @langchain/core peer dependency version to ^0.3.72 in package.json and package-lock.json

fix: update @librechat/agents dependency to version 3.0.0-rc6 in package.json and package-lock.json; refactor stream rate handling in various endpoints

feat: Agent handoff UI

chore: update @librechat/agents dependency to version 3.0.0-rc8 in package.json and package-lock.json

fix: improve hasInfo condition and adjust UI element classes in AgentHandoff component

refactor: remove current fixed agent display from AgentHandoffs component due to redundancy

feat: enhance AgentHandoffs UI with localized beta label and improved layout

chore: update @librechat/agents dependency to version 3.0.0-rc10 in package.json and package-lock.json

feat: add `createSequentialChainEdges` function to add back agent chaining via multi-agents

feat: update `createSequentialChainEdges` call to only provide conversation context between agents

feat: deprecate Agent Chain functionality and update related methods for improved clarity

* chore: update @librechat/agents dependency to version 3.0.0-rc11 in package.json and package-lock.json

* refactor: remove unused addCacheControl function and related imports and import from @librechat/agents

* chore: remove unused i18n keys

* refactor: remove unused format export from index.ts

* chore: update @librechat/agents to v3.0.0-rc13

* chore: remove BEDROCK_LEGACY provider from Providers enum

* chore: update @librechat/agents to version 3.0.2 in package.json

api/server/services/Endpoints/custom/initialize.spec.js

@@ -4,7 +4,6 @@ jest.mock('@librechat/api', () => ({
   ...jest.requireActual('@librechat/api'),
   resolveHeaders: jest.fn(),
   getOpenAIConfig: jest.fn(),
-  createHandleLLMNewToken: jest.fn(),
   getCustomEndpointConfig: jest.fn().mockReturnValue({
     apiKey: 'test-key',
     baseURL: 'https://test.com',