feat: Add unified LiteLLM API management with dashboard UI and CLI integration

- Create ccw-litellm Python package with AbstractEmbedder and AbstractLLMClient interfaces
- Add BaseEmbedder abstraction and factory pattern to codex-lens for pluggable backends
- Implement API Settings dashboard page for provider credentials and custom endpoints
- Add REST API routes for CRUD operations on providers and endpoints
- Extend CLI with --model parameter for custom endpoint routing
- Integrate existing context-cache for @pattern file resolution
- Add provider model registry with predefined models per provider type
- Include i18n translations (en/zh) for all new UI elements

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ccw/src/core/routes/litellm-routes.ts

@@ -0,0 +1,107 @@
+// @ts-nocheck
+/**
+ * LiteLLM Routes Module
+ * Handles all LiteLLM-related API endpoints
+ */
+import type { IncomingMessage, ServerResponse } from 'http';
+import { getLiteLLMClient, getLiteLLMStatus, checkLiteLLMAvailable } from '../../tools/litellm-client.js';
+
+export interface RouteContext {
+  pathname: string;
+  url: URL;
+  req: IncomingMessage;
+  res: ServerResponse;
+  initialPath: string;
+  handlePostRequest: (req: IncomingMessage, res: ServerResponse, handler: (body: unknown) => Promise<any>) => void;
+  broadcastToClients: (data: unknown) => void;
+}
+
+/**
+ * Handle LiteLLM routes
+ * @returns true if route was handled, false otherwise
+ */
+export async function handleLiteLLMRoutes(ctx: RouteContext): Promise<boolean> {
+  const { pathname, url, req, res, initialPath, handlePostRequest } = ctx;
+
+  // API: LiteLLM Status - Check availability and version
+  if (pathname === '/api/litellm/status') {
+    try {
+      const status = await getLiteLLMStatus();
+      res.writeHead(200, { 'Content-Type': 'application/json' });
+      res.end(JSON.stringify(status));
+    } catch (err) {
+      res.writeHead(500, { 'Content-Type': 'application/json' });
+      res.end(JSON.stringify({ available: false, error: err.message }));
+    }
+    return true;
+  }
+
+  // API: LiteLLM Config - Get configuration
+  if (pathname === '/api/litellm/config' && req.method === 'GET') {
+    try {
+      const client = getLiteLLMClient();
+      const config = await client.getConfig();
+      res.writeHead(200, { 'Content-Type': 'application/json' });
+      res.end(JSON.stringify(config));
+    } catch (err) {
+      res.writeHead(500, { 'Content-Type': 'application/json' });
+      res.end(JSON.stringify({ error: err.message }));
+    }
+    return true;
+  }
+
+  // API: LiteLLM Embed - Generate embeddings
+  if (pathname === '/api/litellm/embed' && req.method === 'POST') {
+    handlePostRequest(req, res, async (body) => {
+      const { texts, model = 'default' } = body;
+
+      if (!texts || !Array.isArray(texts)) {
+        return { error: 'texts array is required', status: 400 };
+      }
+
+      if (texts.length === 0) {
+        return { error: 'texts array cannot be empty', status: 400 };
+      }
+
+      try {
+        const client = getLiteLLMClient();
+        const result = await client.embed(texts, model);
+        return { success: true, ...result };
+      } catch (err) {
+        return { error: err.message, status: 500 };
+      }
+    });
+    return true;
+  }
+
+  // API: LiteLLM Chat - Chat with LLM
+  if (pathname === '/api/litellm/chat' && req.method === 'POST') {
+    handlePostRequest(req, res, async (body) => {
+      const { message, messages, model = 'default' } = body;
+
+      // Support both single message and messages array
+      if (!message && (!messages || !Array.isArray(messages))) {
+        return { error: 'message or messages array is required', status: 400 };
+      }
+
+      try {
+        const client = getLiteLLMClient();
+
+        if (messages && Array.isArray(messages)) {
+          // Multi-turn chat
+          const result = await client.chatMessages(messages, model);
+          return { success: true, ...result };
+        } else {
+          // Single message chat
+          const content = await client.chat(message, model);
+          return { success: true, content, model };
+        }
+      } catch (err) {
+        return { error: err.message, status: 500 };
+      }
+    });
+    return true;
+  }
+
+  return false;
+}