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/users/route.ts

@@ -107,7 +107,7 @@ export async function POST(req: NextRequest) {
   // Send email via Supabase Edge Function
   const supabaseUrl = process.env.NEXT_PUBLIC_SUPABASE_URL;
   const supabaseAnonKey = process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY;
-  const siteUrl = process.env.NEXT_PUBLIC_SITE_URL || 'https://broadcastbeat.com';
+  const siteUrl = process.env.NEXT_PUBLIC_SITE_URL || 'https://avbeat.com';
 
   try {
     const emailRes = await fetch(`${supabaseUrl}/functions/v1/send-contributor-invite`, {
@@ -118,7 +118,7 @@ export async function POST(req: NextRequest) {
       },
       body: JSON.stringify({
         email,
-        inviterName: inviterProfile?.full_name || inviterProfile?.email || 'Broadcast Beat Admin',
+        inviterName: inviterProfile?.full_name || inviterProfile?.email || 'AV Beat Admin',
         role: role || 'contributor',
         token,
         message,