Cost monitoring, PTT fix, Devon tuning, WEIRD pool expansion, YT thumbnails, LLM SEO, publish ep37

- Add real-time LLM/TTS cost tracking with live status bar display and post-show reports
- Fix PTT bug where Devon suggestion layout shift stopped recording via mouseleave
- Devon: facts-only during calls, full personality between calls
- Double WEIRD topic pool (109→203), bump weight to 14-25%
- Auto-generate YouTube thumbnails with bold hook text in publish pipeline
- LLM SEO: llms.txt, robots.txt for LLM crawlers, structured data, BreadcrumbList schemas
- Publish episode 37

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/css/style.css

@@ -82,6 +82,11 @@ header {
     color: var(--accent-green);
 }
 
+.clock-cost { font-weight: 700; }
+.cost-low { color: var(--accent-green); }
+.cost-mid { color: #e8a91d; }
+.cost-high { color: var(--accent-red); }
+
 header h1 {
     font-size: 1.5rem;
     font-weight: 700;