wip-banner-system: full banner pool, stack all 300x250s, footer 728x90

Banner spec from Ryan:

- 728x90 header (every page): pool is now LiveU only; rotates when more
  728x90 entries are added to ads.ts.
- 728x90 below main menu on article pages: removed (was the article-top
  AdSlot stub).
- 728x90 footer (every page): replaces the old 300x250 rocket.new
  placeholder in Footer.tsx. Rotates from the same ADS_728X90 pool.
- 300x250 sidebar: now renders EVERY entry in ADS_300X250 stacked
  vertically, shuffled per page-view. Pool: AJA, Zixi, Telycam, LiveU,
  Lectrosonics, Opengear, Studio Hero, Magewell. Adding more entries to
  ads.ts auto-grows the stack.
- 300x600 fixed slot: Blackmagic (Adsanity ad-210571), top of sidebar,
  never rotated.

Implementation:

- ads.ts: Ad interface now allows either src (local image) or adsanity_id
  (iframe). New rotateAll() returns ALL ads of a size shuffled; pickAds
  kept for ArticleBody bounded slots.
- AdImage.tsx: dropped the legacy ADSANITY_CAMPAIGN_MAP label fallback —
  ads.ts is now the single source of truth, so Telycam (no adsanity_id)
  renders its local GIF instead of the iframe.
- SidebarAdStack.tsx: rotateAll(300x250) instead of pickAds with a
  count cap. count prop removed; callers updated.
- NewsArticleDetailClient.tsx: removed article-top 728x90 stub.
- Footer.tsx: 728x90 AdImage in place of the 300x250 placeholder.
- LeaderboardAd.tsx: deleted (was unused after the earlier home-page
  cleanup).
- PENDING_ads.md: rewritten — Adsanity IDs to verify (Studio Hero,
  Blackmagic) and optional local-file upgrades.

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

src/components/Footer.tsx

@@ -7,6 +7,8 @@ import {
   TwitterXIcon,
   FacebookIcon } from
 "@/components/ui/Icons";
+import AdImage from "@/components/AdImage";
+import { ADS_728X90, shuffle } from "@/lib/ads";
 
 // DO NOT OVERRIDE — Footer column structure and link targets
 const footerColumns = [
@@ -61,20 +63,13 @@ const footerColumns = [
 export default function Footer() {
   return (
     <footer className="bg-[#0d0d0d] border-t border-[#222]">
-      {/* Footer Ad Row */}
+      {/* Footer Ad Row — site-wide 728x90 (rotates if multiple in pool) */}
       <div className="max-w-container mx-auto px-4 pt-8 pb-4">
-        <div className="flex flex-wrap justify-center gap-4 mb-8">
-          {/* DO NOT OVERRIDE — footer ad placeholder */}
-          <div className="ad-placeholder w-[300px] h-[250px]">
-            <AppImage
-              src="https://img.rocket.new/generatedImages/rocket_gen_img_189430e3f-1768594771653.png"
-              alt="Advertisement — BroadcastBeat sponsor"
-              width={300}
-              height={250}
-              className="w-full h-full object-contain" />
-            
+        {ADS_728X90.length > 0 && (
+          <div className="flex justify-center mb-8">
+            <AdImage ad={shuffle(ADS_728X90)[0]} page="footer" />
           </div>
-        </div>
+        )}
 
         {/* Multi-column link section */}
         <div className="border-t border-[#222] pt-8 pb-6 grid grid-cols-2 md:grid-cols-4 gap-8">