homepage + NAB: rename 'Coverage Partners' → 'Content Partners' sitewide

SponsorLogoStrip section heading, the section aria-label, the home-page
section comment, and the NAB-2026 page heading + comment all swap to the
new label. No external API or schema references the old phrase, so this
is a pure copy change.

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

src/components/SponsorLogoStrip.tsx

@@ -43,7 +43,7 @@ async function fetchSponsors(): Promise<Sponsor[]> {
       }
     }
 
-    // Layer 2 — pinned coverage partners (directory.featured=true). These
+    // Layer 2 — pinned content partners (directory.featured=true). These
     // surface here whether or not they have an active ad campaign.
     const { data: pinned } = await bb
       .from("tracked_companies")
@@ -68,10 +68,10 @@ export default async function SponsorLogoStrip() {
   if (sponsors.length === 0) return null;
 
   return (
-    <section className="max-w-container mx-auto px-4 py-6 border-t border-b border-[#1a1a1a]" aria-label="Coverage partners">
+    <section className="max-w-container mx-auto px-4 py-6 border-t border-b border-[#1a1a1a]" aria-label="Content partners">
       <div className="flex items-center gap-4 mb-3">
         <span className="text-[10px] uppercase tracking-widest text-[#3b82f6] font-bold">
-          Coverage Partners
+          Content Partners
         </span>
         <div className="flex-1 h-px bg-[#1a1a1a]" />
         <Link href="/advertise" className="text-[10px] text-[#666] hover:text-[#3b82f6] font-mono">