feat: replace Next.js options page with a bun-bundled SPA

[erikbrinkman]

The options page was the only remaining use of Next.js. Its Pages-Router
static export loaded under MV3's script-src 'self' CSP only because
every script was an external self-hosted file; the App Router emits
inline RSC bootstrap scripts the CSP rejects, so there was no path to
modernizing onto it.

Drop Next.js entirely and build the page with bun build, like the
other entry points. options.html is the single source of truth: it
references src/options-main.tsx directly, so bun dev serves it with
HMR and bun build ./options.html derives the production out/ (hashed
JS/CSS/SVG/favicon + rewritten HTML). The result has no chunks and no
inline scripts.

• pages/index.tsx -> components/options-page.tsx, mounted by
  src/options-main.tsx via createRoot
• next/font/google -> @fontsource (woff2 inlined as data URIs by bun)
• next/head -> options.html shell; next/image / StaticImage ->
  with the logo imported through the bundler as a hashed asset
• pack zips the self-contained out/ dir instead of a hand-listed glob
• remove next, @next/eslint-plugin-next, next.config.js, pages/,
  styles.css, the assetPrefix "/out" hack and stale tsconfig entries
• drop 28 dead eslint-disable comments (no eslint is configured)

Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com