ui(avbeat): rename Industry News promoted-coverage badge 'Advertiser' → 'HIGHLIGHT'

src/app/home-page/components/ArticleFeed.tsx:597 — the article-card badge
shown when promoted==='client' said '◆ Advertiser' with a title tooltip
'Advertiser coverage: <name>'. Both copies now say 'HIGHLIGHT' / 'Highlight: <name>'.

Visual treatment (diamond glyph, blue token, uppercase tracking) preserved.
The ★ Featured badge for promoted==='premium' is untouched.

Note: BB still has the original 'Advertiser' label; this change is avbeat-only
unless Ryan asks for it mirrored on BB.

src/app/home-page/components/ArticleFeed.tsx

@@ -593,8 +593,8 @@ export default function ArticleFeed() {
                           </span>
                         )}
                         {promoted === 'client' && (
-                          <span className="font-body text-[9px] font-bold text-[#7aa7d4] bg-[#1D4ED8]/15 border border-[#1D4ED8]/40 px-1.5 py-0.5 rounded uppercase tracking-widest" title={article?.promoted_advertiser ? `Advertiser coverage: ${article.promoted_advertiser}` : 'Advertiser coverage'}>
-                            ◆ Advertiser
+                          <span className="font-body text-[9px] font-bold text-[#7aa7d4] bg-[#1D4ED8]/15 border border-[#1D4ED8]/40 px-1.5 py-0.5 rounded uppercase tracking-widest" title={article?.promoted_advertiser ? `Highlight: ${article.promoted_advertiser}` : 'Highlight'}>
+                            ◆ HIGHLIGHT
                           </span>
                         )}
                         {article?.category && article.category.toLowerCase() !== "legacy" && (