feat: 设置面板 + Provider 扩展 + 构建脚本

- 设置面板：三步引导 / AI 配置 / API Key / 规则管理 / 连接测试
- Provider 重构：统一 OpenAICompatibleProvider 基类，新增 Gemini/Claude/混元/智谱等
- 审查面板 Webview：三 Tab、统计卡片、问题列表、postMessage 通信
- esbuild 构建脚本 + 生产打包 + PMD 下载
- 保存文件自动静态分析（500ms debounce）

src/ai/engine.ts

@@ -1,7 +1,7 @@
 import * as vscode from 'vscode';
 import type { AIProvider } from './providers/base';
 import { createProvider } from './factory';
-import { getAIProvider, getAIModel, getAIEndpoint, getAITemperature, getAITimeout, getAIOutputLanguage, getApiKey } from '../config';
+import { getAIProvider, getAIModel, getAIBaseUrl, getAITemperature, getAITimeout, getAIOutputLanguage, getApiKey } from '../config';
 import type { LinterDiagnostic, CustomRule } from '../types';
 import type {
   AIEngineResult,
@@ -73,11 +73,11 @@ export async function runAIReview(
   }
 
   const providerId = getAIProvider();
-  const endpoint = getAIEndpoint();
+  const baseUrl = getAIBaseUrl();
 
   let provider: AIProvider;
   try {
-    provider = createProvider(providerId, apiKey, endpoint);
+    provider = createProvider(providerId, apiKey, baseUrl);
   } catch (err) {
     return {
       customRuleResults: [],