av: clone broadcastbeat sources + AV Beat rebrand (Phase 1)

- Replaces the prior Rocket scaffold (saved on pre-bb-clone-rollback branch)
- Domain: broadcastbeat.com -> avbeat.com
- Brand: Broadcast Beat -> AV Beat
- Slug: broadcastbeat -> avbeat (package, identifiers)
- Schema fallback: bb -> av (env var name unchanged)
- Placeholder AV BEAT logo (gold->red gradient) at /assets/logos/av.svg
- All BB/RMP logo references repointed

Outstanding before public DNS swap:
  - Supabase av schema bootstrap (mirror of bb tables)
  - WordPress archive import (avbeat-com -> av.articles)
  - Coolify env vars
  - dev-avbeat.onsethost.com staging deploy + visual review

src/app/api/admin/banned-term-alert/route.ts

@@ -13,9 +13,9 @@ export async function POST(request: NextRequest) {
     });
 
     await transport.sendMail({
-      from: `"${process.env.SMTP_FROM_NAME || 'Broadcast Beat'}" <${process.env.SMTP_FROM_EMAIL}>`,
-      to: 'editor@broadcastbeat.com',
-      subject: `[Broadcast Beat] Blocked post attempt — banned term triggered`,
+      from: `"${process.env.SMTP_FROM_NAME || 'AV Beat'}" <${process.env.SMTP_FROM_EMAIL}>`,
+      to: 'editor@avbeat.com',
+      subject: `[AV Beat] Blocked post attempt — banned term triggered`,
       html: `
         <div style="font-family:Arial,sans-serif;max-width:600px;background:#0a0a0a;color:#e5e5e5;padding:32px;border-radius:8px;">
           <h2 style="color:#ef4444;margin:0 0 16px;">Blocked Post Attempt</h2>