feat: 开发采集插件

extension/entrypoints/background.ts

@@ -0,0 +1,23 @@
+// Background Service Worker - 唯一出网口（绕 CORS 取图）
+export default defineBackground(() => {
+  console.log('Seller Helper background started');
+
+  // 点击扩展图标 → 打开 Side Panel
+  chrome.sidePanel.setPanelBehavior({ openPanelOnActionClick: true });
+
+  // 代理图片 fetch（CORS 绕过）
+  chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
+    if (msg.action === 'fetchImage') {
+      fetchImageAsBlob(msg.url)
+        .then(blob => sendResponse({ ok: true, blob }))
+        .catch(err => sendResponse({ ok: false, error: err.message }));
+      return true;  // 保持异步通道
+    }
+  });
+});
+
+async function fetchImageAsBlob(url: string): Promise<Blob> {
+  const res = await fetch(url);
+  if (!res.ok) throw new Error(`HTTP ${res.status}`);
+  return res.blob();
+}