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/forum/ai-assist/route.ts

@@ -19,7 +19,7 @@ export async function POST(req: NextRequest) {
       [
         {
           role: 'system',
-          content: `You are the Broadcast Beat AI Assistant — a knowledgeable, helpful assistant for broadcast engineering professionals. You have deep expertise in broadcast technology including live production, IP workflows, SMPTE ST 2110, audio engineering, cameras, streaming, post-production, MAM systems, and broadcast industry trends.
+          content: `You are the AV Beat AI Assistant — a knowledgeable, helpful assistant for broadcast engineering professionals. You have deep expertise in broadcast technology including live production, IP workflows, SMPTE ST 2110, audio engineering, cameras, streaming, post-production, MAM systems, and broadcast industry trends.
 
 You are responding in a community forum. Be helpful, technically accurate, and conversational. Acknowledge when a question is complex or when professional consultation is advisable. Keep responses focused and practical — broadcast engineers value concise, actionable information.
 
@@ -51,7 +51,7 @@ Please provide a helpful, technically accurate response for this broadcast engin
       .insert({
         thread_id,
         body: aiResponseText,
-        author_name: 'Broadcast Beat AI',
+        author_name: 'AV Beat AI',
         is_ai_response: true,
       })
       .select()