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>

server/index.ts

@@ -12,6 +12,8 @@ import { adminRouter } from './routes/admin.js'
 import { adminProductsRouter } from './routes/adminProducts.js'
 import { adminOrdersRouter } from './routes/adminOrders.js'
 import { uploadRouter } from './routes/upload.js'
+import { adminNostrRouter } from './routes/adminNostr.js'
+import { ordersByPubkeyRouter } from './routes/ordersByPubkey.js'
 
 const app = express()
 const port = Number(process.env.PORT) || 3141
@@ -32,6 +34,8 @@ app.use('/api/admin', adminRouter)
 app.use('/api/admin/products', adminProductsRouter)
 app.use('/api/admin/orders', adminOrdersRouter)
 app.use('/api/admin/upload', uploadRouter)
+app.use('/api/admin', adminNostrRouter)
+app.use('/api/orders/by-pubkey', ordersByPubkeyRouter)
 
 app.get('/api/health', (_req, res) => { res.json({ ok: true, timestamp: new Date().toISOString() }) })