Move caller dialog to Sonnet 4.6, add SearXNG for Devon, and fix stale model ids

Working-tree changes that had accumulated without being committed. The test
updates matter most: tests/test_caller_gen.py was left behind when caller_gen
started requiring voice and age in regulars_included, so the committed tree had
a failing suite that only passed locally.

- Caller dialog moves from Haiku 4.5 to Sonnet 4.6 (~$1/show to ~$3-4/show)
- Grok pinned to x-ai/grok-4.3; grok-4, grok-4-fast and grok-4.1-fast were
  retired from OpenRouter, and llm.py swallows the 404 and returns empty text,
  so a retired id makes callers go silent with nothing in the logs
- Devon's web_search now runs against SearXNG on the NAS
- Assorted TTS, audio, news, cost tracker and control-panel changes
- CLAUDE.md updated to match

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

make_clips.py

@@ -60,7 +60,7 @@ def _llm_request(prompt: str, max_tokens: int = 2048, temperature: float = 0.3,
                     "Content-Type": "application/json",
                 },
                 json={
-                    "model": "anthropic/claude-sonnet-4-5",
+                    "model": "anthropic/claude-sonnet-4.6",
                     "messages": [{"role": "user", "content": prompt}],
                     "max_tokens": max_tokens,
                     "temperature": temperature,