feat(site,docs): aligne le site vitrine et la doc sur l'app « Emerald »

Site (packages/site) : adopte le design system Emerald (polices Inter +
JetBrains Mono variables, tokens sémantiques, thème clair/sombre + bascule)
et met les mockups à jour sur l'app réelle.

- style.css : tokens Emerald (@theme sombre + override html[data-theme=light]) ;
  lib/theme.ts + ThemeToggle.vue + anti-FOUC index.html ; sweep des couleurs
  brutes vers les tokens dans toutes les sections.
- Mockups fidèles à l'IDE multi-projet : HeroMockup (rail ActivityBar au lieu
  de la sidebar large + v obsolète retirée), ShowcaseSection (supervision au
  lieu du dashboard worktree-first, onglets mobiles réels), WorkspaceShowcase
  (diff-add/del, bouton commit accent-solid) ; framing « worktree-first »
  résiduel levé (i18n).
- og-cover.png rafraîchi (carte Emerald).

Docs : README.md + README.fr.md (retrait « Status: MVP », ajout du langage
Emerald + thème clair/sombre/système, VSIX 0.2.0 -> 0.3.0, section Screenshots),
vscode README (VSIX 0.3.0), brand README (thème clair), CHANGELOG daemon 3.2.0.
Captures IDE sombre + clair (brand/screenshot-ide-*.png).

packages/site/src/components/DownloadSection.vue

@@ -16,30 +16,30 @@ const bullets = ['dlNoNode', 'dlBundled', 'dlAutoUpdate'] as const;
 <template>
   <section id="download" class="mx-auto max-w-[1200px] scroll-mt-[84px] px-6 pb-[100px]">
     <div v-reveal class="mb-[40px] max-w-[720px]">
-      <div class="mb-3 font-mono text-xs uppercase tracking-[0.12em] text-emerald-400">{{ t('dlKicker') }}</div>
-      <h2 class="m-0 mb-4 text-[clamp(26px,3vw,38px)] font-semibold leading-[1.15] tracking-[-0.025em] text-zinc-50">
+      <div class="mb-3 font-mono text-xs uppercase tracking-[0.12em] text-accent">{{ t('dlKicker') }}</div>
+      <h2 class="m-0 mb-4 text-[clamp(26px,3vw,38px)] font-semibold leading-[1.15] tracking-[-0.025em] text-fg">
         {{ t('dlTitle') }}
       </h2>
-      <p class="m-0 text-[16.5px] leading-[1.6] text-zinc-400">{{ t('dlBody') }}</p>
+      <p class="m-0 text-[16.5px] leading-[1.6] text-fg-muted">{{ t('dlBody') }}</p>
     </div>
 
     <div v-reveal class="grid gap-4 md:grid-cols-3">
       <div
         v-for="p in platforms"
         :key="p.key"
-        class="flex flex-col gap-1 rounded-[14px] border border-zinc-800 bg-[#09090b] p-5 shadow-card"
+        class="flex flex-col gap-1 rounded-[14px] border border-border bg-surface-0 p-5 shadow-card"
       >
-        <div class="flex items-center gap-2 text-zinc-100">
-          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="text-emerald-400" aria-hidden="true"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4" /><polyline points="7 10 12 15 17 10" /><line x1="12" x2="12" y1="15" y2="3" /></svg>
+        <div class="flex items-center gap-2 text-fg">
+          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="text-accent" aria-hidden="true"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4" /><polyline points="7 10 12 15 17 10" /><line x1="12" x2="12" y1="15" y2="3" /></svg>
           <span class="text-[15px] font-semibold">{{ t(p.key) }}</span>
         </div>
-        <span class="pl-[26px] font-mono text-[12.5px] text-zinc-500">{{ t(p.hint) }}</span>
+        <span class="pl-[26px] font-mono text-[12.5px] text-fg-subtle">{{ t(p.hint) }}</span>
       </div>
     </div>
 
     <ul v-reveal class="mt-6 flex flex-wrap gap-x-6 gap-y-2">
-      <li v-for="b in bullets" :key="b" class="flex items-center gap-2 text-[14px] text-zinc-300">
-        <svg width="15" height="15" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.4" stroke-linecap="round" stroke-linejoin="round" class="text-emerald-400" aria-hidden="true"><path d="M20 6 9 17l-5-5" /></svg>
+      <li v-for="b in bullets" :key="b" class="flex items-center gap-2 text-[14px] text-fg-muted">
+        <svg width="15" height="15" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.4" stroke-linecap="round" stroke-linejoin="round" class="text-accent" aria-hidden="true"><path d="M20 6 9 17l-5-5" /></svg>
         {{ t(b) }}
       </li>
     </ul>
@@ -49,7 +49,7 @@ const bullets = ['dlNoNode', 'dlBundled', 'dlAutoUpdate'] as const;
         :href="RELEASES"
         target="_blank"
         rel="noopener"
-        class="inline-flex items-center gap-2 rounded-lg bg-emerald-500 px-4 py-2.5 text-[14.5px] font-semibold text-emerald-950 no-underline transition-colors hover:bg-emerald-400 focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-emerald-500/70"
+        class="inline-flex items-center gap-2 rounded-lg bg-accent-solid px-4 py-2.5 text-[14.5px] font-semibold text-white no-underline transition-colors hover:bg-accent-hover focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-accent/70"
       >
         {{ t('dlGet') }}
       </a>
@@ -57,12 +57,12 @@ const bullets = ['dlNoNode', 'dlBundled', 'dlAutoUpdate'] as const;
         :href="DESKTOP_SRC"
         target="_blank"
         rel="noopener"
-        class="inline-flex items-center gap-2 rounded-lg border border-zinc-800 px-4 py-2.5 text-[14.5px] font-medium text-zinc-300 no-underline transition-colors hover:border-emerald-500/50 hover:text-emerald-400 focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-emerald-500/70"
+        class="inline-flex items-center gap-2 rounded-lg border border-border px-4 py-2.5 text-[14.5px] font-medium text-fg-muted no-underline transition-colors hover:border-accent/50 hover:text-accent focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-accent/70"
       >
         {{ t('dlSource') }}
       </a>
     </div>
 
-    <p v-reveal class="mt-4 max-w-[720px] text-[13.5px] leading-[1.55] text-zinc-500">{{ t('dlNote') }}</p>
+    <p v-reveal class="mt-4 max-w-[720px] text-[13.5px] leading-[1.55] text-fg-subtle">{{ t('dlNote') }}</p>
   </section>
 </template>