ads: route all clicks through advertising.RMP.com/r/<id> + cache-aware banner reads

Two compounding bugs caused 0 clicks since May 22:

1. lib/ads.ts exported ADS_728X90 / ADS_300X250 / FIXED_300X600 as
   IIFE-evaluated module constants. They captured the FALLBACK array
   at module-load time, before the centralized RMP banner cache
   populates. Every render that referenced them got FALLBACK banners
   whose click_url was the direct advertiser URL — bypassing the
   centralized click logger entirely. 300x250s escaped because every
   page reads them via rotateAll() at render time.

2. Even when the new RMP-cache banners did render, click_url pointed
   at www.RMP.com/<property>/<slug>, which logs to adv.banner_clicks.
   The RMP analytics dashboard reads bb.ad_clicks. Repointed click
   URLs at advertising.RMP.com/r/<campaign_id> so all clicks land in
   the single table the dashboard queries.

Files: lib/ads.ts (remove broken IIFE exports + repoint click_url),
SidebarAdStack, Header, Footer, and 9 pages (reading-list, forum,
forum/thread, search, gear, technology, authors, show-coverage x2).

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

src/components/Footer.tsx

@@ -8,7 +8,7 @@ import {
   FacebookIcon } from
 "@/components/ui/Icons";
 import AdImage from "@/components/AdImage";
-import { ADS_728X90, shuffle } from "@/lib/ads";
+import { pickAds } from "@/lib/ads";
 
 // DO NOT OVERRIDE — Footer column structure and link targets
 const footerColumns = [
@@ -65,9 +65,9 @@ export default function Footer() {
     <footer className="bg-[#0d0d0d] border-t border-[#222]">
       {/* Footer Ad Row — site-wide 728x90 (rotates if multiple in pool) */}
       <div className="max-w-container mx-auto px-4 pt-8 pb-4">
-        {ADS_728X90.length > 0 && (
+        {pickAds("728x90", 1).length > 0 && (
           <div className="flex justify-center mb-8">
-            <AdImage ad={shuffle(ADS_728X90)[0]} page="footer" />
+            <AdImage ad={pickAds("728x90", 1)[0]} page="footer" />
           </div>
         )}