End-state of the multi-step KTD-5 / KTD-6 / U8 work. The knoway sidecar
is no longer reachable from server code; the router is required at boot
and now owns chat completions, TTS synthesis, and voice catalog listing.
Highlights:
- LLM_ROUTER_MASTER_KEY becomes required; app.ts drops the graceful-
skip branch and the chat fallback fetch path is gone.
- /audio/speech and /audio/voices route through new routeTts /
listTtsVoices entries that reuse the chat key-rotator + per-attempt
timeout + abort propagation.
- DEFAULT_CHAT_MODEL / DEFAULT_TTS_MODEL move from env to configKV so
default-model swaps are hot-reloadable via Pub/Sub.
- GATEWAY_BASE_URL removed from env schema, .env, .env.local, smoke,
verification harness. Redis upstream-voices cache deleted — catalogs
come from in-process adapter JSON.
- routeTts splits adapter error contract by ApiError statusCode:
4xx propagates without fallback; 5xx folds into the network-failure
fallback path. handleTTS wraps billing + span attribute in try/finally
to plug a span leak when ttsMeter.accumulate() throws.
- seed-router-config.ts rewritten with --merge (default) / --reset /
--dry-run modes and env-var key handoff (OPENROUTER_KEY / AZURE_KEY /
DASHSCOPE_KEY) so prod seed flows never put plaintext on the CLI.
Adds DashScope CosyVoice seeding.
Docs (CLAUDE.md, architecture-overview.md, transport-and-routes.md)
reflect the new boundary. verifications/llm-router.md replaces the
overstated "U1-U9 shipped" line with an evidence-vs-pending table.
Tests: full 40-file / 343-case server suite green. New regressions pin
ApiError 4xx → no-fallback, ApiError 5xx → fallback, TTS billing
failure → span closed and error propagated.