feat: 集成 SearXNG 元搜索引擎，支持 JSON API 搜索替代四引擎 HTML 解析

- 新增 SearXNG 配置模态框，支持 API 地址、引擎列表、语言、安全搜索等参数
- 顶部添加独立 🔍 搜索按钮，带启用状态小绿点
- 启用后 web_search 走 SearXNG JSON API（70+ 引擎聚合）
- 禁用时回退原有 Bing+百度+搜狗+360 四引擎 HTML 解析方案
- 认证 Key 通过 HTTP Header Authorization: Bearer 传递，非必填
- 配置持久化到 SQLite settings 表

src/renderer/components/searxng-modal.ts

@@ -0,0 +1,134 @@
+/**
+ * SearXNG 配置模态框
+ * 配置 SearXNG 元搜索引擎的 API 地址和参数，支持启用/禁用切换
+ */
+
+import { state, KEYS } from '../state/state.js';
+import type { ChatDB } from '../db/chat-db.js';
+import { logInfo, logSuccess } from '../services/log-service.js';
+
+/** 默认 SearXNG 配置 */
+const DEFAULTS = {
+  enabled: false,
+  url: 'https://search.metona.cn',
+  engines: 'google,bing,duckduckgo,wikipedia',
+  language: 'zh-CN',
+  safesearch: 1,
+  time_range: '',
+  max_results: 20,
+  auth_key: '',
+};
+
+let modalEl: HTMLElement;
+let initialized = false;
+
+/** SearXNG 运行时配置缓存（主进程搜索时通过 IPC 读取，渲染进程通过此变量快速访问） */
+export let searxngConfig = { ...DEFAULTS };
+
+/** 写入配置到 SQLite + 更新运行时缓存 */
+async function saveConfig(db: ChatDB): Promise<void> {
+  await db.saveSetting('searxng_enabled', searxngConfig.enabled);
+  await db.saveSetting('searxng_url', searxngConfig.url);
+  await db.saveSetting('searxng_engines', searxngConfig.engines);
+  await db.saveSetting('searxng_language', searxngConfig.language);
+  await db.saveSetting('searxng_safesearch', searxngConfig.safesearch);
+  await db.saveSetting('searxng_time_range', searxngConfig.time_range);
+  await db.saveSetting('searxng_max_results', searxngConfig.max_results);
+  await db.saveSetting('searxng_auth_key', searxngConfig.auth_key);
+  logSuccess('SearXNG 配置已保存');
+}
+
+/** 从 SQLite 加载配置到运行时缓存 */
+export async function loadSearxngConfig(db: ChatDB): Promise<void> {
+  searxngConfig.enabled = await db.getSetting('searxng_enabled', DEFAULTS.enabled);
+  searxngConfig.url = await db.getSetting('searxng_url', DEFAULTS.url);
+  searxngConfig.engines = await db.getSetting('searxng_engines', DEFAULTS.engines);
+  searxngConfig.language = await db.getSetting('searxng_language', DEFAULTS.language);
+  searxngConfig.safesearch = await db.getSetting('searxng_safesearch', DEFAULTS.safesearch);
+  searxngConfig.time_range = await db.getSetting('searxng_time_range', DEFAULTS.time_range);
+  searxngConfig.max_results = await db.getSetting('searxng_max_results', DEFAULTS.max_results);
+  searxngConfig.auth_key = await db.getSetting('searxng_auth_key', DEFAULTS.auth_key);
+  logInfo('SearXNG 配置已加载', searxngConfig.enabled ? `已启用: ${searxngConfig.url}` : '未启用');
+}
+
+/** 刷新 UI 控件以匹配当前配置 */
+function syncFormFromConfig(): void {
+  (document.querySelector('#searxngUrl') as HTMLInputElement).value = searxngConfig.url;
+  (document.querySelector('#searxngEngines') as HTMLInputElement).value = searxngConfig.engines;
+  (document.querySelector('#searxngLanguage') as HTMLSelectElement).value = searxngConfig.language;
+  (document.querySelector('#searxngSafeSearch') as HTMLSelectElement).value = String(searxngConfig.safesearch);
+  (document.querySelector('#searxngTimeRange') as HTMLSelectElement).value = searxngConfig.time_range || '';
+  (document.querySelector('#searxngMaxResults') as HTMLInputElement).value = String(searxngConfig.max_results);
+  (document.querySelector('#searxngAuthKey') as HTMLInputElement).value = searxngConfig.auth_key;
+  const toggle = document.querySelector('#toggleSearxngEnabled') as HTMLInputElement;
+  toggle.checked = searxngConfig.enabled;
+  updateEnabledUI(searxngConfig.enabled);
+}
+
+/** 启用/禁用状态切换 UI */
+function updateEnabledUI(enabled: boolean): void {
+  const badge = document.querySelector('#searxngBadge') as HTMLElement;
+  const toggle = document.querySelector('#toggleSearxngEnabled') as HTMLInputElement;
+  const iconDot = document.querySelector('#searxngIconDot') as HTMLElement;
+  if (badge) {
+    badge.textContent = enabled ? '🟢 已启用' : '⚪ 未启用';
+    badge.className = enabled ? 'searxng-badge enabled' : 'searxng-badge';
+  }
+  if (toggle) toggle.checked = enabled;
+  if (iconDot) {
+    iconDot.className = enabled ? 'searxng-icon-dot enabled' : 'searxng-icon-dot';
+  }
+}
+
+export function initSearxngModal(): void {
+  if (initialized) return;
+  modalEl = document.querySelector('#searxngModal') as HTMLElement;
+
+  // ── 打开模态框 ──
+  document.querySelector('#btnSearxng')!.addEventListener('click', async () => {
+    // 重新加载配置（可能在别处被修改）
+    const db = state.get<ChatDB | null>(KEYS.DB);
+    if (db) await loadSearxngConfig(db);
+    syncFormFromConfig();
+    modalEl.style.display = '';
+  });
+
+  // ── 关闭模态框 ──
+  document.querySelector('#btnCloseSearxng')!.addEventListener('click', () => {
+    modalEl.style.display = 'none';
+  });
+  modalEl.addEventListener('click', (e) => {
+    if (e.target === modalEl) modalEl.style.display = 'none';
+  });
+
+  // ── 启用/禁用开关 ──
+  document.querySelector('#toggleSearxngEnabled')!.addEventListener('change', async (e) => {
+    const checked = (e.target as HTMLInputElement).checked;
+    searxngConfig.enabled = checked;
+    updateEnabledUI(checked);
+    const db = state.get<ChatDB | null>(KEYS.DB);
+    if (db) await db.saveSetting('searxng_enabled', checked);
+    logInfo('SearXNG', checked ? '已启用' : '已禁用');
+  });
+
+  // ── 保存按钮 ──
+  document.querySelector('#btnSaveSearxng')!.addEventListener('click', async () => {
+    searxngConfig.url = (document.querySelector('#searxngUrl') as HTMLInputElement).value.trim();
+    searxngConfig.engines = (document.querySelector('#searxngEngines') as HTMLInputElement).value.trim();
+    searxngConfig.language = (document.querySelector('#searxngLanguage') as HTMLSelectElement).value;
+    searxngConfig.safesearch = parseInt((document.querySelector('#searxngSafeSearch') as HTMLSelectElement).value);
+    searxngConfig.time_range = (document.querySelector('#searxngTimeRange') as HTMLSelectElement).value;
+    searxngConfig.max_results = parseInt((document.querySelector('#searxngMaxResults') as HTMLInputElement).value) || 20;
+    searxngConfig.auth_key = (document.querySelector('#searxngAuthKey') as HTMLInputElement).value.trim();
+    const db = state.get<ChatDB | null>(KEYS.DB);
+    if (db) await saveConfig(db);
+    updateEnabledUI(searxngConfig.enabled);
+  });
+
+  initialized = true;
+}
+
+/** 外部调用关闭模态框（ESC 键等） */
+export function closeSearxngModal(): void {
+  if (modalEl) modalEl.style.display = 'none';
+}

src/renderer/index.html

@@ -72,6 +72,12 @@
                     <circle cx="12" cy="12" r="3"/><path d="M12 1v2M12 21v2M4.22 4.22l1.42 1.42M18.36 18.36l1.42 1.42M1 12h2M21 12h2M4.22 19.78l1.42-1.42M18.36 5.64l1.42-1.42"/>
                 </svg>
             </button>
+            <button class="icon-btn searxng-btn" id="btnSearxng" title="SearXNG 搜索配置">
+                <span class="searxng-icon-dot" id="searxngIconDot"></span>
+                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                    <circle cx="11" cy="11" r="8"/><line x1="21" y1="21" x2="16.65" y2="16.65"/>
+                </svg>
+            </button>
         </div>
     </header>
 
@@ -699,6 +705,100 @@
 <!-- ═══════════════ Toast 通知容器 ═══════════════ -->
 <div class="toast-container" id="toastContainer"></div>
 
+<!-- ═══════════════ SearXNG 配置模态框 ═══════════════ -->
+<div class="modal-overlay" id="searxngModal" style="display:none;">
+    <div class="modal" style="max-width:640px;">
+        <div class="modal-header">
+            <h3>🔍 SearXNG 元搜索引擎</h3>
+            <button class="icon-btn" id="btnCloseSearxng">
+                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                    <line x1="18" y1="6" x2="6" y2="18"/><line x1="6" y1="6" x2="18" y2="18"/>
+                </svg>
+            </button>
+        </div>
+        <div class="modal-body">
+            <div class="setting-group">
+                <label class="setting-label">
+                    <span class="searxng-badge" id="searxngBadge">⚪ 未启用</span>
+                    <label class="toggle-label" style="margin-left:auto;display:inline-flex;">
+                        <input type="checkbox" id="toggleSearxngEnabled">
+                        <span class="toggle-slider"></span>
+                    </label>
+                </label>
+                <p class="text-muted" style="font-size:11px;margin-top:4px;">
+                    启用后，联网搜索将使用 SearXNG 元搜索引擎（隐私保护、70+ 引擎聚合），替代内置的四引擎 HTML 解析方案。
+                </p>
+            </div>
+
+            <div class="setting-group">
+                <label class="setting-label">SearXNG API 地址</label>
+                <input class="setting-input" id="searxngUrl" type="url" placeholder="https://search.metona.cn" style="margin-bottom:6px;">
+                <p class="text-muted" style="font-size:11px;">SearXNG 实例的根地址，无需带 /search 路径</p>
+            </div>
+
+            <div class="setting-group">
+                <label class="setting-label">搜索引擎</label>
+                <input class="setting-input" id="searxngEngines" type="text" placeholder="google,bing,duckduckgo,wikipedia" style="margin-bottom:6px;">
+                <p class="text-muted" style="font-size:11px;">逗号分隔的引擎列表。常用: google, bing, duckduckgo, wikipedia, brave, qwant, startpage</p>
+            </div>
+
+            <div style="display:grid;grid-template-columns:1fr 1fr;gap:14px;">
+                <div class="setting-group">
+                    <label class="setting-label">语言</label>
+                    <select class="setting-input" id="searxngLanguage" style="margin-bottom:0;">
+                        <option value="zh-CN">简体中文</option>
+                        <option value="zh-TW">繁體中文</option>
+                        <option value="en">English</option>
+                        <option value="ja">日本語</option>
+                        <option value="ko">한국어</option>
+                        <option value="">自动检测</option>
+                    </select>
+                </div>
+                <div class="setting-group">
+                    <label class="setting-label">安全搜索</label>
+                    <select class="setting-input" id="searxngSafeSearch" style="margin-bottom:0;">
+                        <option value="0">关闭</option>
+                        <option value="1">中等</option>
+                        <option value="2">严格</option>
+                    </select>
+                </div>
+                <div class="setting-group">
+                    <label class="setting-label">时间范围</label>
+                    <select class="setting-input" id="searxngTimeRange" style="margin-bottom:0;">
+                        <option value="">不限</option>
+                        <option value="day">最近一天</option>
+                        <option value="week">最近一周</option>
+                        <option value="month">最近一月</option>
+                        <option value="year">最近一年</option>
+                    </select>
+                </div>
+                <div class="setting-group">
+                    <label class="setting-label">单次结果数</label>
+                    <input class="setting-input" id="searxngMaxResults" type="number" min="1" max="50" step="1" value="20" style="margin-bottom:0;">
+                </div>
+            </div>
+
+            <div class="setting-group">
+                <label class="setting-label">🔑 认证 Key（非必填）</label>
+                <input class="setting-input" id="searxngAuthKey" type="password" placeholder="留空则不发送认证" style="margin-bottom:6px;">
+                <p class="text-muted" style="font-size:11px;">SearXNG 实例的 API 认证密钥，通过 HTTP Header <code>Authorization: Bearer xxx</code> 传递。需配合 Nginx 反向代理验证</p>
+            </div>
+
+            <div class="modal-actions">
+                <div style="flex:1;"></div>
+                <button class="btn btn-primary" id="btnSaveSearxng">💾 保存配置</button>
+            </div>
+
+            <div style="margin-top:16px;padding:12px;background:var(--bg-layer);border-radius:var(--radius-md);">
+                <p style="font-size:11px;color:var(--text-secondary);margin:0;">
+                    💡 <strong>提示：</strong>SearXNG 是开源元搜索引擎，不追踪用户、不记录隐私。
+                    需要自行部署或使用公共实例。API 端点格式：<code>{{URL}}/search?q={{query}}&format=json</code>
+                </p>
+            </div>
+        </div>
+    </div>
+</div>
+
 <!-- ═══════════════ 应用入口 ════════════════ -->
 <script type="module" src="./main.ts"></script>
 </body>

src/renderer/main.ts

@@ -30,6 +30,7 @@ import { initToolConfirmModal } from './components/tool-confirm-modal.js';
 import { initWorkspacePanel, clearToolCardsExternal, clearTerminalExternal, switchToTab } from './components/workspace-panel.js';
 import { initLogPanel, addLog } from './services/log-service.js';
 import { logInfo, logSuccess, logError, logDebug, logInit, logWarn } from './services/log-service.js';
+import { initSearxngModal, closeSearxngModal, loadSearxngConfig } from './components/searxng-modal.js';
 import type { ChatSession } from './types.js';
 
 // ─── v4.0 数据迁移：IndexedDB → SQLite ───
@@ -337,12 +338,14 @@ async function init(): Promise<void> {
     initTokenDashboard();
     initWorkspacePanel();
     setupDesktopIntegration();
+    initSearxngModal();
 
     bindGlobalEvents();
 
     await checkConnection();
     await loadModels();
     await initMemoryManager();
+    await loadSearxngConfig(db);
     logInit('所有组件已就绪');
 
     const savedModel = await db.getSetting('selectedModel', '');
@@ -458,6 +461,7 @@ function bindGlobalEvents(): void {
       closeLightbox();
       closeToolsModal();
       closeTokenDashboard();
+      closeSearxngModal();
       (document.querySelector('#helpModal') as HTMLElement).style.display = 'none';
       (document.querySelector('#memoryModal') as HTMLElement).style.display = 'none';
     }

src/renderer/styles/style.css

@@ -1983,6 +1983,41 @@ html, body {
     .messages { max-width: 900px; }
 }
 
+/* ═══ SearXNG 搜索配置 ═══ */
+.searxng-btn {
+    position: relative;
+}
+
+.searxng-icon-dot {
+    position: absolute;
+    top: 4px;
+    right: 4px;
+    width: 8px;
+    height: 8px;
+    border-radius: 50%;
+    background: var(--text-disabled);
+    transition: var(--transition);
+    z-index: 2;
+}
+
+.searxng-icon-dot.enabled {
+    background: var(--success);
+    box-shadow: 0 0 6px rgba(74, 174, 107, 0.5);
+}
+
+.searxng-badge {
+    display: inline-flex;
+    align-items: center;
+    font-size: 13px;
+    font-weight: 600;
+    color: var(--text-tertiary);
+    transition: var(--transition);
+}
+
+.searxng-badge.enabled {
+    color: var(--success);
+}
+
 /* ── 选中文本 ── */
 ::selection {
     background: rgba(232, 115, 74, 0.2);