feat(extension): 浏览器插件 P1 MVP

新建 BillNote_extension/ 工作空间（基于 vitesse-webext 骨架，Vue 3 + Vite + UnoCSS + MV3）。

P1 MVP 范围：
- popup：自动读当前 tab URL，识别 Bilibili / YouTube / 抖音 / 快手；提交 /generate_note 后轮询 /task_status；展示 markdown，复制 + 下载 .md
- options：后端地址输入与连通性测试；从 /get_all_providers + /get_models_by_provider 拉供应商/模型列表；默认画质、截图/跳转、笔记风格
- chrome.storage.local 持久化设置与最近 30 个任务，popup 重开恢复进行中任务
- markdown 里的 /static/screenshots 路径在渲染前重写为绝对地址

后端：CORS 改用 regex，新增允许 chrome-extension:// 与 moz-extension:// 源（同时保留 localhost / 127.0.0.1 / tauri.localhost）。无新增 backend endpoint。

P2-P4（content script 悬浮按钮、cookie 直通、side panel、思维导图、RAG 问答）保留 stub 文件，不在本次范围。

去掉 vitesse-webext 自带的 simple-git-hooks postinstall 配置——它会在仓库根装 pre-commit 钩子去跑 pnpm lint-staged，但仓库根没有 package.json，会破坏所有提交流。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

BillNote_extension/vite.config.mts

@@ -0,0 +1,115 @@
+/// <reference types="vitest" />
+
+import { dirname, relative } from 'node:path'
+import type { UserConfig } from 'vite'
+import { defineConfig } from 'vite'
+import Vue from '@vitejs/plugin-vue'
+import Icons from 'unplugin-icons/vite'
+import IconsResolver from 'unplugin-icons/resolver'
+import Components from 'unplugin-vue-components/vite'
+import AutoImport from 'unplugin-auto-import/vite'
+import UnoCSS from 'unocss/vite'
+import { isDev, port, r } from './scripts/utils'
+import packageJson from './package.json'
+
+export const sharedConfig: UserConfig = {
+  root: r('src'),
+  resolve: {
+    alias: {
+      '~/': `${r('src')}/`,
+    },
+  },
+  define: {
+    __DEV__: isDev,
+    __NAME__: JSON.stringify(packageJson.name),
+  },
+  plugins: [
+    Vue(),
+
+    AutoImport({
+      imports: [
+        'vue',
+        {
+          'webextension-polyfill': [
+            ['=', 'browser'],
+          ],
+        },
+      ],
+      dts: r('src/auto-imports.d.ts'),
+    }),
+
+    // https://github.com/antfu/unplugin-vue-components
+    Components({
+      dirs: [r('src/components')],
+      // generate `components.d.ts` for ts support with Volar
+      dts: r('src/components.d.ts'),
+      resolvers: [
+        // auto import icons
+        IconsResolver({
+          prefix: '',
+        }),
+      ],
+    }),
+
+    // https://github.com/antfu/unplugin-icons
+    Icons(),
+
+    // https://github.com/unocss/unocss
+    UnoCSS(),
+
+    // rewrite assets to use relative path
+    {
+      name: 'assets-rewrite',
+      enforce: 'post',
+      apply: 'build',
+      transformIndexHtml(html, { path }) {
+        return html.replace(/"\/assets\//g, `"${relative(dirname(path), '/assets')}/`)
+      },
+    },
+  ],
+  optimizeDeps: {
+    include: [
+      'vue',
+      '@vueuse/core',
+      'webextension-polyfill',
+    ],
+    exclude: [
+      'vue-demi',
+    ],
+  },
+}
+
+export default defineConfig(({ command }) => ({
+  ...sharedConfig,
+  base: command === 'serve' ? `http://localhost:${port}/` : '/dist/',
+  server: {
+    port,
+    hmr: {
+      host: 'localhost',
+    },
+    origin: `http://localhost:${port}`,
+  },
+  build: {
+    watch: isDev
+      ? {}
+      : undefined,
+    outDir: r('extension/dist'),
+    emptyOutDir: false,
+    sourcemap: isDev ? 'inline' : false,
+    // https://developer.chrome.com/docs/webstore/program_policies/#:~:text=Code%20Readability%20Requirements
+    terserOptions: {
+      mangle: false,
+    },
+    rollupOptions: {
+      input: {
+        options: r('src/options/index.html'),
+        popup: r('src/popup/index.html'),
+        sidepanel: r('src/sidepanel/index.html'),
+      },
+    },
+  },
+  test: {
+    globals: true,
+    environment: 'jsdom',
+  },
+}))