feat: 添加 LSP 代码诊断功能

- 实现 LSP 客户端，支持与语言服务器通信
- 支持多种语言: TypeScript, Python, Go, Rust, C/C++ 等
- write_file/edit_file 工具集成 LSP 诊断，写入后自动检查代码错误
- 添加 CLI 命令管理语言服务器 (ai-assist lsp list/install/info)
- 智能等待机制：首次启动 LSP 等待 2s，后续仅需 300ms
- 将 read_file/write_file/edit_file 设为核心工具，确保文件操作使用正确的工具
- 更新系统提示词，引导 AI 使用文件工具而非 bash 命令

src/tools/filesystem/edit_file.ts

@@ -4,6 +4,7 @@ import type { ToolResult } from '../../types/index.js';
 import type { ToolWithMetadata } from '../types.js';
 import { loadDescription } from '../load_description.js';
 import { getPermissionManager } from '../../permission/index.js';
+import { touchFile, getFormattedFileDiagnostics, isLanguageSupported } from '../../lsp/index.js';
 
 export const editFileTool: ToolWithMetadata = {
   name: 'edit_file',
@@ -13,7 +14,7 @@ export const editFileTool: ToolWithMetadata = {
     category: 'filesystem',
     description: '编辑文件内容（查找替换）',
     keywords: ['edit', 'file', 'replace', 'modify', 'change', 'update', '编辑', '文件', '替换', '修改', '更新'],
-    deferLoading: true,
+    deferLoading: false, // 核心工具，始终可用
   },
   parameters: {
     path: {
@@ -87,9 +88,27 @@ export const editFileTool: ToolWithMetadata = {
       const newContent = content.replace(oldString, newString);
       await fs.writeFile(absolutePath, newContent, 'utf-8');
 
+      let output = `文件已编辑: ${absolutePath}`;
+
+      // 如果支持 LSP，通知语言服务器并获取诊断
+      if (isLanguageSupported(absolutePath)) {
+        try {
+          const isFirstStart = await touchFile(absolutePath, false);
+          // 首次启动需要更长时间，后续只需短暂等待
+          const waitTime = isFirstStart ? 2000 : 300;
+          await new Promise(resolve => setTimeout(resolve, waitTime));
+          const diagnostics = await getFormattedFileDiagnostics(absolutePath);
+          if (diagnostics) {
+            output += `\n\n⚠️ 代码检查发现问题，请修复:${diagnostics}`;
+          }
+        } catch {
+          // LSP 错误不影响主流程
+        }
+      }
+
       return {
         success: true,
-        output: `文件已编辑: ${absolutePath}`,
+        output,
       };
     } catch (error) {
       return {

src/tools/filesystem/read_file.ts

@@ -13,7 +13,7 @@ export const readFileTool: ToolWithMetadata = {
     category: 'filesystem',
     description: '读取文件内容',
     keywords: ['read', 'file', 'content', 'cat', 'view', 'open', '读取', '文件', '内容', '查看', '打开'],
-    deferLoading: true,
+    deferLoading: false, // 核心工具，始终可用
   },
   parameters: {
     path: {

src/tools/filesystem/write_file.ts

@@ -4,6 +4,7 @@ import type { ToolResult } from '../../types/index.js';
 import type { ToolWithMetadata } from '../types.js';
 import { loadDescription } from '../load_description.js';
 import { getPermissionManager } from '../../permission/index.js';
+import { touchFile, getFormattedFileDiagnostics, isLanguageSupported } from '../../lsp/index.js';
 
 export const writeFileTool: ToolWithMetadata = {
   name: 'write_file',
@@ -13,7 +14,7 @@ export const writeFileTool: ToolWithMetadata = {
     category: 'filesystem',
     description: '写入文件内容',
     keywords: ['write', 'file', 'save', 'create', '写入', '文件', '保存', '创建', '新建'],
-    deferLoading: true,
+    deferLoading: false, // 核心工具，始终可用
   },
   parameters: {
     path: {
@@ -61,9 +62,28 @@ export const writeFileTool: ToolWithMetadata = {
     try {
       await fs.mkdir(path.dirname(absolutePath), { recursive: true });
       await fs.writeFile(absolutePath, content, 'utf-8');
+
+      let output = `文件已写入: ${absolutePath}`;
+
+      // 如果支持 LSP，通知语言服务器并获取诊断
+      if (isLanguageSupported(absolutePath)) {
+        try {
+          const isFirstStart = await touchFile(absolutePath, true);
+          // 首次启动需要更长时间，后续只需短暂等待
+          const waitTime = isFirstStart ? 2000 : 300;
+          await new Promise(resolve => setTimeout(resolve, waitTime));
+          const diagnostics = await getFormattedFileDiagnostics(absolutePath);
+          if (diagnostics) {
+            output += `\n\n⚠️ 代码检查发现问题，请修复:${diagnostics}`;
+          }
+        } catch {
+          // LSP 错误不影响主流程
+        }
+      }
+
       return {
         success: true,
-        output: `文件已写入: ${absolutePath}`,
+        output,
       };
     } catch (error) {
       return {