fix(contrast,brand): full audit sweep — white-on-white + cross-component renames

- forum/page.tsx: text-white → navy on TopThreads, Following feed, Discover feed cards, search input, select, category grid, Community Guidelines; greys lightened where applicable for new white surface
- forum/[slug]/page.tsx: same sweep for category page (h1, h2, thread rows, new-thread form, search/sort bar) + hover:bg-[#1e2a3a] → slate-200
- forum/user/[username]/page.tsx: text-[#cccccc]/[#bfbfbf]/[#e0e0e0] + bg-[#222] tag chip + #9ca3af labels → readable on white card
- authors/[slug]/page.tsx: profile contact/facts cards readable
- search/page.tsx: h1 + h2 navy + hover slate
- news/[slug]/NewsArticleDetailClient.tsx: toast color
- news/NewsPageClient.tsx: import cleanExcerpt, strip HTML from listing excerpts
- privacy/terms/page.tsx: h1 + h2 + body greys to readable navy/slate
- error.tsx: page-level text to navy + button border slate
- about/page.tsx: page body text + Stat/Block cards to white surface w/ navy text
- Header.tsx: mobile hamburger + dropdown links → readable navy + slate border
- NotificationCenter.tsx: hover + unread bg flipped to light blue
- AISuggestedArticles.tsx: hover bg → slate-200
- Footer.tsx: link greys to #475569 + #DCE6F2 borders
- AskBBAI.tsx: copy rename 'BB AI' → 'AV Beat AI' (greeting, button, header, aria)

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

src/components/AskBBAI.tsx

@@ -15,7 +15,7 @@ export default function AskBBAI() {
     {
       role: "assistant",
       content:
-        "Hi — I'm BB AI. Ask me anything about broadcast, production, or post technology. I'll cite sources from the AV Beat archive.",
+        "Hi — I'm AV Beat AI. Ask me anything about pro AV, live production, or display technology. I'll cite sources from the AV Beat archive.",
     },
   ]);
   const [err, setErr] = useState<string | null>(null);
@@ -68,13 +68,13 @@ export default function AskBBAI() {
           type="button"
           onClick={() => setOpen(true)}
           className="fixed bottom-16 right-6 z-40 bg-black text-white rounded-full pl-5 pr-5 py-3 shadow-2xl flex items-center gap-3 hover:bg-zinc-900 transition-colors"
-          aria-label="Ask BB AI"
+          aria-label="Ask AV Beat AI"
         >
           <span className="relative inline-block w-3 h-3">
             <span className="absolute inset-0 rounded-full bg-[var(--color-text-info,#60a5fa)]" />
             <span className="bb-ring" />
           </span>
-          <span className="font-serif">Ask BB AI</span>
+          <span className="font-serif">Ask AV Beat AI</span>
         </button>
       )}
 
@@ -82,7 +82,7 @@ export default function AskBBAI() {
         <div
           ref={drawerRef}
           role="dialog"
-          aria-label="Ask BB AI"
+          aria-label="Ask AV Beat AI"
           className="fixed right-0 top-0 bottom-0 z-50 w-full sm:w-[420px] bg-[#0a0a0a] border-l border-[#DCE6F2] flex flex-col"
         >
           <header className="flex items-center justify-between px-5 py-4 border-b border-[#DCE6F2]">
@@ -91,7 +91,7 @@ export default function AskBBAI() {
                 <span className="absolute inset-0 rounded-full bg-[var(--color-text-info,#60a5fa)]" />
                 <span className="bb-ring" />
               </span>
-              <h2 className="font-serif text-lg font-semibold text-white">BB AI</h2>
+              <h2 className="font-serif text-lg font-semibold text-white">AV Beat AI</h2>
             </div>
             <button
               onClick={() => setOpen(false)}