Ep13 publish, MLX whisper, voicemail system, hero redesign, massive topic expansion

- Switch whisper transcription from faster-whisper (CPU) to lightning-whisper-mlx (GPU)
- Fix word_timestamps hanging, use ffprobe for accurate duration
- Add Cloudflare Pages Worker for SignalWire voicemail fallback when server offline
- Add voicemail sync on startup, delete tracking, save feature
- Add /feed RSS proxy to _worker.js (was broken by worker taking over routing)
- Redesign website hero section: ghost buttons, compact phone, plain text links
- Rewrite caller prompts for faster point-getting and host-following
- Expand TOPIC_CALLIN from ~250 to 547 entries across 34 categories
- Add new categories: biology, psychology, engineering, math, geology, animals,
  work, money, books, movies, relationships, health, language, true crime,
  drunk/high/unhinged callers
- Remove bad Inworld voices (Pixie, Dominus), reduce repeat caller frequency
- Add audio monitor device routing, uvicorn --reload-dir fix
- Publish episode 13

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -24,9 +24,8 @@
 
 ## Running the App
 ```bash
-# Start backend
-cd /Users/lukemacneil/ai-podcast
-python -m uvicorn backend.main:app --reload --host 0.0.0.0 --port 8000
+# Start backend — ALWAYS use --reload-dir to avoid CPU thrashing from file watchers
+python -m uvicorn backend.main:app --reload --reload-dir backend --host 0.0.0.0 --port 8000
 
 # Or use run.sh
 ./run.sh