feat(vscode-ide-companion): improve CLI path detection and error handling

- Move determineNodePathForCli function to dedicated cliPathDetector.ts file
- Enhance error handling with specific guidance for permission issues
- Add detailed error messages for different failure scenarios
- Improve logging for debugging CLI path detection issues

This change improves the reliability of CLI path detection by providing better error messages and handling edge cases more gracefully.

packages/vscode-ide-companion/src/constants/acpSchema.ts

@@ -0,0 +1,60 @@
+/**
+ * @license
+ * Copyright 2025 Qwen Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * ACP (Agent Communication Protocol) Method Definitions
+ *
+ * This file defines the protocol methods for communication between
+ * the VSCode extension (Client) and the qwen CLI (Agent/Server).
+ */
+
+/**
+ * Methods that the Agent (CLI) implements and receives from Client (VSCode)
+ *
+ * Status in qwen CLI:
+ * ✅ initialize - Protocol initialization
+ * ✅ authenticate - User authentication
+ * ✅ session/new - Create new session
+ * ✅ session/load - Load existing session (v0.2.4+)
+ * ✅ session/list - List available sessions (v0.2.4+)
+ * ✅ session/prompt - Send user message to agent
+ * ✅ session/cancel - Cancel current generation
+ * ✅ session/save - Save current session
+ */
+export const AGENT_METHODS = {
+  authenticate: 'authenticate',
+  initialize: 'initialize',
+  session_cancel: 'session/cancel',
+  session_list: 'session/list',
+  session_load: 'session/load',
+  session_new: 'session/new',
+  session_prompt: 'session/prompt',
+  session_save: 'session/save',
+} as const;
+
+/**
+ * Methods that the Client (VSCode) implements and receives from Agent (CLI)
+ *
+ * Status in VSCode extension:
+ * ✅ fs/read_text_file - Read file content
+ * ✅ fs/write_text_file - Write file content
+ * ✅ session/request_permission - Request user permission for tool execution
+ * ✅ session/update - Stream session updates (notification)
+ */
+export const CLIENT_METHODS = {
+  fs_read_text_file: 'fs/read_text_file',
+  fs_write_text_file: 'fs/write_text_file',
+  session_request_permission: 'session/request_permission',
+  session_update: 'session/update',
+} as const;
+
+/**
+ * Custom methods (not in standard ACP protocol)
+ * These are VSCode extension specific extensions
+ */
+export const CUSTOM_METHODS = {
+  session_list: 'session/list',
+} as const;