brand: neon BROADCAST BEAT wordmark (SVG + PNG)

- SVG logo at public/brand/logo.svg with pink-magenta BROADCAST,
  cyan BEAT, cyan heartbeat waveform underline, ™ mark, and
  "THE PULSE OF PRODUCTION INTELLIGENCE" tagline
- PNG renders at 1x (1200x320), 2x (2400x640), small (600x160)
- Header swapped from /assets/images/logo.png to /brand/logo.svg

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/Header.tsx

@@ -381,12 +381,12 @@ export default function Header() {
               {/* Logo */}
               <Link href="/home-page" className="flex-shrink-0 focus:outline-none focus-visible:ring-2 focus-visible:ring-[#3b82f6] focus-visible:ring-offset-1 focus-visible:ring-offset-[#111]">
                 <AppImage
-                  src="/assets/images/logo.png"
-                  alt="Broadcast Beat logo"
-                  width={200}
-                  height={26}
+                  src="/brand/logo.svg"
+                  alt="Broadcast Beat — The Pulse of Production Intelligence"
+                  width={260}
+                  height={70}
                   priority={true}
-                  className="h-7 w-auto object-contain"
+                  className="h-9 w-auto object-contain"
                 />
               </Link>