feat: scaffold Antonym fashion store

Anonymous Bitcoin-only fashion e-commerce with:
- Vue 3 + Tailwind 4 frontend with glassmorphism dark/light design system
- Express 5 + SQLite backend with BTCPay Server integration
- Nostr identity (NIP-07/keypair) for anonymous purchase tracking
- ChaCha20-Poly1305 encrypted shipping addresses
- Admin panel with order/product/stock management
- SVG logo splash animation with clip-path reveal
- 5 seeded products across 4 categories

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/admin/AdminShell.vue

@@ -0,0 +1,107 @@
+<script setup lang="ts">
+import { useRouter } from 'vue-router'
+import { useAdmin } from '@/composables/useAdmin'
+import ThemeToggle from '@/components/ui/ThemeToggle.vue'
+
+const router = useRouter()
+const { logout } = useAdmin()
+
+async function handleLogout() {
+  await logout()
+  router.push({ name: 'admin-login' })
+}
+</script>
+
+<template>
+  <div class="admin-shell">
+    <aside class="admin-sidebar glass-strong">
+      <div class="sidebar-header">
+        <router-link to="/" class="brand">Antonym</router-link>
+        <span class="admin-badge">Admin</span>
+      </div>
+
+      <nav class="sidebar-nav">
+        <router-link :to="{ name: 'admin-orders' }" class="nav-item">Orders</router-link>
+        <router-link :to="{ name: 'admin-products' }" class="nav-item">Products</router-link>
+      </nav>
+
+      <div class="sidebar-footer">
+        <ThemeToggle />
+        <button class="logout-btn" @click="handleLogout">Logout</button>
+      </div>
+    </aside>
+
+    <main class="admin-main">
+      <router-view />
+    </main>
+  </div>
+</template>
+
+<style scoped>
+.admin-shell { display: flex; min-height: 100vh; }
+
+.admin-sidebar {
+  width: 220px;
+  padding: 1.25rem;
+  display: flex;
+  flex-direction: column;
+  border-radius: 0;
+  border-top: none;
+  border-bottom: none;
+  border-left: none;
+  position: sticky;
+  top: 0;
+  height: 100vh;
+}
+
+.sidebar-header { display: flex; align-items: center; gap: 0.5rem; margin-bottom: 2rem; }
+
+.brand { font-weight: 700; font-size: 1.125rem; color: var(--text-primary); text-decoration: none; }
+
+.admin-badge {
+  font-size: 0.625rem;
+  font-weight: 600;
+  text-transform: uppercase;
+  letter-spacing: 0.08em;
+  padding: 0.15rem 0.4rem;
+  border-radius: var(--radius-sm);
+  background: var(--accent);
+  color: #000;
+}
+
+.sidebar-nav { display: flex; flex-direction: column; gap: 0.25rem; flex: 1; }
+
+.nav-item {
+  padding: 0.5rem 0.75rem;
+  border-radius: var(--radius-sm);
+  color: var(--text-secondary);
+  text-decoration: none;
+  font-size: 0.875rem;
+  font-weight: 500;
+  transition: all var(--transition-fast);
+}
+
+.nav-item:hover { background: var(--glass-bg); color: var(--text-primary); }
+.nav-item.router-link-active { background: var(--glass-bg-strong); color: var(--text-primary); }
+
+.sidebar-footer {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding-top: 1rem;
+  border-top: 1px solid var(--glass-border);
+}
+
+.logout-btn {
+  background: none;
+  border: none;
+  color: var(--text-muted);
+  font-size: 0.8125rem;
+  cursor: pointer;
+  transition: color var(--transition-fast);
+}
+
+.logout-btn:hover { color: var(--error); }
+
+.admin-main { flex: 1; padding: 2rem; max-width: 1000px; }
+</style>