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>

packages/website/src/App.vue

@@ -0,0 +1,38 @@
+<script setup lang="ts">
+import { darkTheme } from 'naive-ui'
+import { NConfigProvider, NMessageProvider } from 'naive-ui'
+import { useTheme } from '@/composables/useTheme'
+import { getThemeOverrides } from '@client/styles/theme'
+import SiteHeader from '@/components/layout/SiteHeader.vue'
+import SiteFooter from '@/components/layout/SiteFooter.vue'
+
+const { isDark } = useTheme()
+</script>
+
+<template>
+  <NConfigProvider :theme="isDark ? darkTheme : undefined" :theme-overrides="getThemeOverrides(isDark)">
+    <NMessageProvider>
+      <div class="website-app">
+        <SiteHeader />
+        <main class="website-main">
+          <router-view />
+        </main>
+        <SiteFooter />
+      </div>
+    </NMessageProvider>
+  </NConfigProvider>
+</template>
+
+<style scoped lang="scss">
+.website-app {
+  min-height: 100vh;
+  display: flex;
+  flex-direction: column;
+  background: var(--bg-primary);
+  color: var(--text-primary);
+}
+
+.website-main {
+  flex: 1;
+}
+</style>