feat: 添加 LLM Content Extractor 浏览器扩展

- 支持框选区域提取网页内容
- 支持整页内容提取
- 输出格式：Markdown/JSON/XML
- 自动复制到剪贴板

browser-extension/popup.js

@@ -0,0 +1,72 @@
+document.addEventListener('DOMContentLoaded', () => {
+  const selectBtn = document.getElementById('selectBtn');
+  const fullPageBtn = document.getElementById('fullPageBtn');
+  const copyLastBtn = document.getElementById('copyLastBtn');
+  const formatSelect = document.getElementById('formatSelect');
+  const status = document.getElementById('status');
+
+  function showStatus(message, type) {
+    status.textContent = message;
+    status.className = `status ${type}`;
+    setTimeout(() => {
+      status.className = 'status';
+    }, 3000);
+  }
+
+  // 框选区域提取
+  selectBtn.addEventListener('click', async () => {
+    const [tab] = await chrome.tabs.query({ active: true, currentWindow: true });
+    const format = formatSelect.value;
+    
+    await chrome.tabs.sendMessage(tab.id, { 
+      action: 'startSelection',
+      format: format
+    });
+    
+    window.close();
+  });
+
+  // 提取整页内容
+  fullPageBtn.addEventListener('click', async () => {
+    const [tab] = await chrome.tabs.query({ active: true, currentWindow: true });
+    const format = formatSelect.value;
+    
+    try {
+      const response = await chrome.tabs.sendMessage(tab.id, { 
+        action: 'extractFullPage',
+        format: format
+      });
+      
+      if (response && response.success) {
+        showStatus('✅ 内容已复制到剪贴板', 'success');
+      } else {
+        showStatus('❌ 提取失败', 'error');
+      }
+    } catch (err) {
+      showStatus('❌ 请刷新页面后重试', 'error');
+    }
+  });
+
+  // 复制上次结果
+  copyLastBtn.addEventListener('click', async () => {
+    const result = await chrome.storage.local.get('lastExtraction');
+    if (result.lastExtraction) {
+      await navigator.clipboard.writeText(result.lastExtraction);
+      showStatus('✅ 已复制上次结果', 'success');
+    } else {
+      showStatus('❌ 暂无历史记录', 'error');
+    }
+  });
+
+  // 恢复上次选择的格式
+  chrome.storage.local.get('format', (result) => {
+    if (result.format) {
+      formatSelect.value = result.format;
+    }
+  });
+
+  // 保存格式选择
+  formatSelect.addEventListener('change', () => {
+    chrome.storage.local.set({ format: formatSelect.value });
+  });
+});