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/api/newsletter/subscribers/route.ts

@@ -141,7 +141,7 @@ export async function POST(req: NextRequest) {
       <!-- Header -->
       <div style="background:#111;border-bottom:2px solid #1D4ED8;padding:24px 32px;">
         <h1 style="color:#1D4ED8;font-size:22px;margin:0;font-weight:bold;">AV Beat</h1>
-        <p style="color:#555;font-size:12px;margin:4px 0 0;">News & Intelligence for Pro AV, Live Production & Display Tech</p>
+        <p style="color:#555;font-size:12px;margin:4px 0 0;">Pro AV, Display and Live Production Tech</p>
       </div>
       <!-- Body -->
       <div style="padding:32px;">