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

public/assets/logos/av.svg

@@ -0,0 +1,13 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 360 96" width="360" height="96">
+  <defs>
+    <linearGradient id="av-grad" x1="0" x2="1">
+      <stop offset="0%" stop-color="#FFB300"/>
+      <stop offset="55%" stop-color="#FF6B00"/>
+      <stop offset="100%" stop-color="#D60701"/>
+    </linearGradient>
+  </defs>
+  <g font-family="Plus Jakarta Sans, sans-serif" font-weight="800">
+    <text x="0" y="44" font-size="40" fill="url(#av-grad)" letter-spacing="2">AVB</text>
+    <text x="0" y="82" font-size="20" fill="#f4f4f6" letter-spacing="2.5" opacity="0.85">AV Beat</text>
+  </g>
+</svg>