feat(avbeat): brand-blue nav, navy card text, tagline rename, hide Industry News dates + Topics row, force-dynamic homepage

- Main nav background → brand-blue #1D4ED8 (sampled from logo emblem).
- Nav link text → white with darker-blue hover bg so contrast holds.
- Article card title fixed from #e0e0e0 to navy #0F172A (was unreadable on the new white surface).
- Industry News card date row removed.
- /news Topics filter chip row removed.
- /news article hover from stark #111 to light-blue #EFF6FF tint matching the brand.
- Tagline 'News & Intelligence for Pro AV, Live Production & Display Tech' renamed to 'Pro AV, Display and Live Production Tech' across Header, RSS feed, newsletter welcome template, root layout title, page title, OG/Twitter tags.
- Homepage page.tsx now has `export const dynamic = 'force-dynamic'` + `revalidate = 0` so the hero (FeaturedBentoFromDb) actually re-renders against the live supabase row (previously the page was being statically prerendered which masked DB-driven hero swaps).

src/app/rss/route.ts

@@ -44,7 +44,7 @@ export async function GET() {
     <title>AV Beat</title>
     <link>${SITE_URL}</link>
     <atom:link href="${SITE_URL}/rss" rel="self" type="application/rss+xml" />
-    <description>News &amp; Intelligence for Pro AV, Live Production &amp; Display Tech</description>
+    <description>Pro AV, Display and Live Production Tech</description>
     <language>en-us</language>
     <lastBuildDate>${new Date().toUTCString()}</lastBuildDate>
 ${items}