feat: Add packages/site — landing vitrine (Vue 3 + Tailwind 4)

- Scaffold packages/site with 11 Vue components: hero (animated terminal), features, showcase, work groups, how-it-works, security, FAQ accordion, footer
- i18n EN/FR via vue-i18n with 82+ keys, autodetect navigator.language, toggle without reload
- Animated timeline (terminal, dialog, toast) ported from design, scroll-reveal, copy buttons (2 instances)
- Self-hosted JetBrains Mono fonts (@fontsource), optimized assets (mark 28KB, og-cover 1200×630)
- SEO: canonical, og:image, theme-color, robots.txt, sitemap.xml for git-arboretum.com
- Monorepo integration (decoupled from npm release): build:site / dev:site / preview:site scripts
- CI: add build:site step to ci.yml for early detection; create .gitea/workflows/prod.yml for FTPS deploy (lftp mirror) to git-arboretum.com
- Validated builds ✓ and UI rendering (EN/FR headless test) ✓

packages/site/src/components/FinalCta.vue

@@ -0,0 +1,61 @@
+<script setup lang="ts">
+import { useI18n } from 'vue-i18n';
+import { useCopy, INSTALL_COMMAND } from '../composables/useCopy';
+import IconGitea from './icons/IconGitea.vue';
+import IconCopy from './icons/IconCopy.vue';
+
+const { t } = useI18n();
+const { copied, copy } = useCopy();
+const REPO = 'https://git.lidge.fr/johanleroy/git-arboretum';
+</script>
+
+<template>
+  <section class="mx-auto max-w-[1200px] px-6 pb-[100px]">
+    <div
+      v-reveal
+      class="rounded-[20px] border border-zinc-800 px-6 py-[clamp(36px,5vw,64px)] text-center"
+      style="background: radial-gradient(120% 140% at 50% 0%, rgba(16, 185, 129, 0.1), transparent 60%), #0c0c0e"
+    >
+      <img
+        src="/assets/arboretum-mark.png"
+        alt=""
+        width="52"
+        height="52"
+        class="mx-auto mb-5 block h-[52px] w-[52px] object-contain"
+      />
+      <h2 class="m-0 mb-3.5 text-[clamp(30px,4vw,46px)] font-bold leading-[1.08] tracking-[-0.03em] text-zinc-50">
+        {{ t('ctaTitle') }}
+      </h2>
+      <p class="mx-auto mb-7 max-w-[480px] text-[17px] text-zinc-400">{{ t('ctaBody') }}</p>
+
+      <div
+        class="mx-auto flex max-w-[460px] items-stretch overflow-hidden rounded-[10px] border border-zinc-800 bg-zinc-950"
+      >
+        <div class="flex min-w-0 flex-1 items-center gap-2.5 overflow-x-auto whitespace-nowrap px-4 font-mono text-sm">
+          <span class="text-emerald-400">$</span><span class="text-zinc-200">{{ INSTALL_COMMAND }}</span>
+        </div>
+        <button
+          type="button"
+          aria-label="Copy install command"
+          class="inline-flex flex-none items-center gap-[7px] border-l border-zinc-800 bg-zinc-900 px-4 font-mono text-[13px] font-semibold text-zinc-300 transition-colors hover:bg-zinc-800 hover:text-emerald-400 focus-visible:outline-2 focus-visible:-outline-offset-2 focus-visible:outline-emerald-500/70"
+          @click="copy()"
+        >
+          <IconCopy :size="15" />
+          <span aria-live="polite">{{ copied ? t('copied') : t('copy') }}</span>
+        </button>
+      </div>
+
+      <div class="mt-[18px]">
+        <a
+          :href="REPO"
+          target="_blank"
+          rel="noopener"
+          class="inline-flex items-center gap-2 text-[14.5px] text-zinc-400 no-underline transition-colors hover:text-emerald-400"
+        >
+          <IconGitea :size="16" />
+          {{ t('ctaSource') }}
+        </a>
+      </div>
+    </div>
+  </section>
+</template>