Extends the TTS lease from #100912 (4e3feb8bbb) beyond built-in local
engines: when the configured tts.provider is user-declared, acquiring
the first lease and releasing the last one now reach it, so a
self-hosted TTS server can preload its model when read-aloud / voice
conversation turns on and unload when it turns off (Discord request).
- agent/tts_provider.py: TTSProvider gains concrete no-op warm() /
release() (not abstract — existing plugins are unaffected).
- tools/tts_tool.py: _signal_user_tts_provider() forwards the lease
hook; plugin providers get warm()/release(), command providers run
optional `warm_command` / `release_command` (config.yaml, under
tts.providers.<name>) through the existing _run_command_tts helper
on a daemon thread — best-effort, output discarded, failures at
debug. warm_tts_provider() and release_tts_provider() call it.
- tests/tools/test_tts_lifecycle_leases.py: fake plugin provider and
fake command provider observe warm/release through acquire/release
lease (both fail on main with action == "noop").
- docs: features/tts.md — lease section, command-provider optional
keys table, plugin optional hooks.
Desktop "Read replies aloud" / voice conversation, TUI and CLI /voice tts
now hold a lease on the TTS engine. Acquiring pre-loads the configured
provider (piper/kittentts model into the same LRU slot synthesis reads;
lazily-installed cloud SDKs), so the first spoken reply no longer pays the
model load as dead air. Releasing the last lease across surfaces unloads
resident local models.
- tools/tts_tool.py: warm_tts_provider / release_tts_provider /
acquire_tts_lease / release_tts_lease over a _LOCAL_TTS_MODEL_CACHES
registry; piper/kittentts loaders extracted so warm-up and synthesis
share one resolution path.
- web_server: POST /api/audio/tts-lease (profile-scoped, off-loop,
failures reported in body never as HTTP errors).
- tui_gateway voice.toggle + cli.py /voice tts|on|off wire the lease.
- desktop: lib/tts-lease.ts (dedupe, per-lease serialization, latest
intent wins) driven from useComposerVoice; setTtsLease API client.
- docs: features/tts.md section.
Live (real piper, isolated HERMES_HOME): first synthesis 988ms cold →
92ms after the toggle warmed the engine; release drops the model.