feat: placeholder images, Nostr inbox, order lookup, SEO, bigger logo

- 5 SVG placeholder product images (minimal dark style with watermark initials)
- Seed data updated to reference .svg placeholders
- Nostr DM inbox in admin (Messages tab) with shop npub display
- GET /api/admin/nostr-info endpoint for shop pubkey
- My Orders page: customers look up orders by NIP-07 Nostr identity
- GET /api/orders/by-pubkey/:pubkey endpoint with hex validation
- SeoMeta component for OG/Twitter meta tags
- SEO meta on HomeView and ProductView
- Base OG meta tags in index.html
- "My Orders" link in shop header nav
- Splash logo doubled in size on desktop (680px max)

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

src/components/SeoMeta.vue

@@ -0,0 +1,44 @@
+<script setup lang="ts">
+import { watchEffect } from 'vue'
+
+const props = defineProps<{
+  title?: string
+  description?: string
+  image?: string
+}>()
+
+const siteName = 'Antonym'
+const defaultDescription = 'Fashion for the sovereign individual. Bitcoin only. No accounts. No tracking.'
+const defaultImage = '/logos/logo.svg'
+
+watchEffect(() => {
+  const fullTitle = props.title ? `${props.title} — ${siteName}` : siteName
+  document.title = fullTitle
+
+  setMeta('description', props.description || defaultDescription)
+  setMeta('og:title', fullTitle)
+  setMeta('og:description', props.description || defaultDescription)
+  setMeta('og:image', props.image || defaultImage)
+  setMeta('og:type', 'website')
+  setMeta('og:site_name', siteName)
+  setMeta('twitter:card', 'summary_large_image')
+  setMeta('twitter:title', fullTitle)
+  setMeta('twitter:description', props.description || defaultDescription)
+  setMeta('twitter:image', props.image || defaultImage)
+})
+
+function setMeta(name: string, content: string) {
+  const attr = name.startsWith('og:') || name.startsWith('twitter:') ? 'property' : 'name'
+  let el = document.querySelector(`meta[${attr}="${name}"]`)
+  if (!el) {
+    el = document.createElement('meta')
+    el.setAttribute(attr, name)
+    document.head.appendChild(el)
+  }
+  el.setAttribute('content', content)
+}
+</script>
+
+<template>
+  <slot />
+</template>

src/components/admin/AdminShell.vue

@@ -23,6 +23,7 @@ async function handleLogout() {
       <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>
+        <router-link :to="{ name: 'admin-messages' }" class="nav-item">Messages</router-link>
       </nav>
 
       <div class="sidebar-footer">

src/components/layout/ShopHeader.vue

@@ -14,6 +14,7 @@ const { itemCount } = useCart()
 
       <nav class="nav-links">
         <router-link to="/" class="nav-link">Shop</router-link>
+        <router-link to="/my-orders" class="nav-link">My Orders</router-link>
       </nav>
 
       <div class="header-actions">

src/components/splash/LogoSplash.vue

@@ -107,7 +107,7 @@ onMounted(() => {
 
 /* --- Logo phase --- */
 .splash-logo {
-  width: min(60vw, 340px);
+  width: min(80vw, 680px);
   height: auto;
 }