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/scripts/manifest.ts

@@ -0,0 +1,10 @@
+import fs from 'fs-extra'
+import { getManifest } from '../src/manifest'
+import { log, r } from './utils'
+
+export async function writeManifest() {
+  await fs.writeJSON(r('extension/manifest.json'), await getManifest(), { spaces: 2 })
+  log('PRE', 'write manifest.json')
+}
+
+writeManifest()

BillNote_extension/scripts/prepare.ts

@@ -0,0 +1,40 @@
+// generate stub index.html files for dev entry
+import { execSync } from 'node:child_process'
+import fs from 'fs-extra'
+import chokidar from 'chokidar'
+import { isDev, log, port, r } from './utils'
+
+/**
+ * Stub index.html to use Vite in development
+ */
+async function stubIndexHtml() {
+  const views = ['options', 'popup', 'sidepanel']
+
+  for (const view of views) {
+    await fs.ensureDir(r(`extension/dist/${view}`))
+    let data = await fs.readFile(r(`src/${view}/index.html`), 'utf-8')
+    data = data
+      .replace('"./main.ts"', `"http://localhost:${port}/${view}/main.ts"`)
+      .replace('<div id="app"></div>', '<div id="app">Vite server did not start</div>')
+    await fs.writeFile(r(`extension/dist/${view}/index.html`), data, 'utf-8')
+    log('PRE', `stub ${view}`)
+  }
+}
+
+function writeManifest() {
+  execSync('npx esno ./scripts/manifest.ts', { stdio: 'inherit' })
+}
+
+writeManifest()
+
+if (isDev) {
+  stubIndexHtml()
+  chokidar.watch(r('src/**/*.html'))
+    .on('change', () => {
+      stubIndexHtml()
+    })
+  chokidar.watch([r('src/manifest.ts'), r('package.json')])
+    .on('change', () => {
+      writeManifest()
+    })
+}

BillNote_extension/scripts/utils.ts

@@ -0,0 +1,12 @@
+import { resolve } from 'node:path'
+import process from 'node:process'
+import { bgCyan, black } from 'kolorist'
+
+export const port = Number(process.env.PORT || '') || 3303
+export const r = (...args: string[]) => resolve(__dirname, '..', ...args)
+export const isDev = process.env.NODE_ENV !== 'production'
+export const isFirefox = process.env.EXTENSION === 'firefox'
+
+export function log(name: string, message: string) {
+  console.log(black(bgCyan(` ${name} `)), message)
+}