fix: resolve GitHub issues #63, #66, #67, #68, #69, #70

- #70: Fix API Key Tester URL handling - normalize trailing slashes before
  version suffix detection to prevent double-slash URLs like //models
- #69: Fix memory embedder ignoring CodexLens config - add error handling
  for CodexLensConfig.load() with fallback to defaults
- #68: Fix ccw cli using wrong Python environment - add getCodexLensVenvPython()
  to resolve correct venv path on Windows/Unix
- #67: Fix LiteLLM API Provider test endpoint - actually test API key connection
  instead of just checking ccw-litellm installation
- #66: Fix help-routes.ts path configuration - use correct 'ccw-help' directory
  name and refactor getIndexDir to pure function
- #63: Fix CodexLens install state refresh - add cache invalidation after
  config save in codexlens-manager.js

Also includes targeted unit tests for the URL normalization logic.

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

ccw/src/tools/litellm-client.ts

@@ -10,14 +10,36 @@
  */
 
 import { spawn } from 'child_process';
-import { promisify } from 'util';
+import { existsSync } from 'fs';
+import { join } from 'path';
+import { homedir } from 'os';
 
 export interface LiteLLMConfig {
-  pythonPath?: string;  // Default 'python'
+  pythonPath?: string;  // Default: CodexLens venv Python
   configPath?: string;  // Configuration file path
   timeout?: number;     // Default 60000ms
 }
 
+// Platform-specific constants for CodexLens venv
+const IS_WINDOWS = process.platform === 'win32';
+const CODEXLENS_VENV = join(homedir(), '.codexlens', 'venv');
+const VENV_BIN_DIR = IS_WINDOWS ? 'Scripts' : 'bin';
+const PYTHON_EXECUTABLE = IS_WINDOWS ? 'python.exe' : 'python';
+
+/**
+ * Get the Python path from CodexLens venv
+ * Falls back to system 'python' if venv doesn't exist
+ * @returns Path to Python executable
+ */
+export function getCodexLensVenvPython(): string {
+  const venvPython = join(CODEXLENS_VENV, VENV_BIN_DIR, PYTHON_EXECUTABLE);
+  if (existsSync(venvPython)) {
+    return venvPython;
+  }
+  // Fallback to system Python if venv not available
+  return 'python';
+}
+
 export interface ChatMessage {
   role: 'system' | 'user' | 'assistant';
   content: string;
@@ -51,7 +73,7 @@ export class LiteLLMClient {
   private timeout: number;
 
   constructor(config: LiteLLMConfig = {}) {
-    this.pythonPath = config.pythonPath || 'python';
+    this.pythonPath = config.pythonPath || getCodexLensVenvPython();
     this.configPath = config.configPath;
     this.timeout = config.timeout || 60000;
   }

ccw/src/tools/litellm-executor.ts

@@ -3,7 +3,7 @@
  * Integrates with context-cache for file packing and LiteLLM client for API calls
  */
 
-import { getLiteLLMClient } from './litellm-client.js';
+import { getLiteLLMClient, getCodexLensVenvPython } from './litellm-client.js';
 import { handler as contextCacheHandler } from './context-cache.js';
 import {
   findEndpointById,
@@ -179,7 +179,7 @@ export async function executeLiteLLMEndpoint(
     }
 
     const client = getLiteLLMClient({
-      pythonPath: 'python',
+      pythonPath: getCodexLensVenvPython(),
       timeout: 120000, // 2 minutes
     });