feat: add landing page and docs website (#537)

* feat: add landing page and docs website package

Add packages/website — a Vue 3 + Naive UI static site with landing page
and documentation, sharing the Pure Ink monochrome design with the main
app. Features: particle network hero animation, screenshot carousel,
feature grid, install guide tabs, GitHub star history, scroll reveal
animations, and Chinese/English bilingual support.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* chore: add favicon to website package

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: use dynamic theme param for star history chart

Switch from CSS media query to JS-based dark mode detection so the
star-history SVG matches the current theme toggle state.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: resolve TypeScript strict mode errors in website components

- Remove unused isDark import in HeroSection
- Add null check for canvas parent element
- Rename unused img loop variable in ScreenshotsSection
- Remove unused NIcon import in SiteHeader

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: resolve TS narrowing errors in canvas resize closure

Use canvasRef.value directly inside resize() with local null check
instead of relying on outer closure narrowing.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

package.json

@@ -55,6 +55,9 @@
     "test": "vitest run",
     "test:watch": "vitest",
     "test:coverage": "vitest run --coverage",
+    "dev:website": "vite --config vite.config.website.ts",
+    "build:website": "vite build --config vite.config.website.ts",
+    "preview:website": "vite preview --config vite.config.website.ts",
     "openapi:generate": "node scripts/generate-openapi.mjs"
   },
   "files": [