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/index.html

@@ -26,6 +26,9 @@
                     <span class="clock-divider">|</span>
                     <span class="clock-label">Est. Final:</span>
                     <span class="clock-value clock-estimate" id="clock-estimate">0:00</span>
+                    <span class="clock-divider">|</span>
+                    <span class="clock-label">Cost:</span>
+                    <span class="clock-value clock-cost" id="clock-cost">$0.00</span>
                 </span>
             </div>
         </header>