v0.3.18

The self-sufficiency release. Two long-standing "works on my network / works after four terminal commands" walls came down: model downloads now find a reachable Hugging Face endpoint on their own (no more restricted-network first-run dead-ends), and IndexTTS-2 — previously the only engine that demanded a manual clone-venv-install ritual — installs itself with one click. Under the hood, a test-debt sweep hardened the suite that guards all of it.

### Added

- **IndexTTS-2 installs itself now — one click in Settings → Engines.** The emotion-controlled cloning engine used to demand four terminal steps (clone the repo, create a venv, `uv pip install`, set an environment variable); the row now has an Install button that does all of it — source fetch (git, with a no-git tarball fallback), an isolated venv that keeps its `transformers<5` away from the app, the ~6 GB model weights (via your configured/auto-selected Hugging Face endpoint), and configuration — with step-by-step progress, a disk-space check before anything is written, and resumable repair if anything is interrupted. The engine is usable the moment the job finishes, no restart; existing manual installs are detected and left untouched, and the manual steps remain as a collapsible fallback. The provisioner is parametrized so future sidecar engines (MOSS-v1.5, dots.tts, Confucius4) can reuse it. (#1083)

- **Model downloads now find a reachable Hugging Face endpoint on their own.** On networks where huggingface.co is blocked or slow (the class of first-run dead-ends behind #984), the app quietly probes the official endpoint and the hf-mirror.com community mirror, picks whichever actually works, remembers the choice, and re-checks only when a download fails or the pick goes stale — so a restricted-network first run reaches a working voice instead of a wall of connection errors. Anyone who already set a mirror (env var, pref, or Settings) stays exactly where they pointed: explicit choices are never auto-switched, and Settings → Models → Hugging Face mirror now shows the automatic pick with its measured latency plus a "Test again" button. Probes only touch the two download hosts — no geo-IP, no telemetry — and every download stays checksum-verified by `huggingface_hub` regardless of endpoint. (#1082)

### Fixed

- **Concurrent settings writes can no longer drop each other.** Two parts of the app saving preferences at the same moment (say, an engine install finishing while you change a setting) could silently lose whichever save landed first; preference writes are now serialized, with a regression test. Found and fixed as part of the IndexTTS-2 installer work. (#1083)

### CI

- **Test-suite debt sweep.** Exports coverage (26 new tests, which caught two real router bugs), fp16 default-dtype leak instrumentation, and a suite-order pollution class root-caused at its source — the checks that guard every release got stricter. (#1081)
### Windows x64 artifacts

```
f7d26a94af61fad908c21adb9da8f63196f8de58bdd4900562c09b0838c11348 *OmniVoice Studio_0.3.18_x64_en-US.msi
d05d99953b477ab59271b4671b91665bf40802bb9b33e27e29ff51cbf80c83a0 *OmniVoice Studio_0.3.18_x64_en-US.msi.sig
```


### Linux x64 artifacts

```
f83cc7bd935ebabfba77872da0290fd91863d9ae74d65948bcb3d1742332a465  OmniVoice Studio_0.3.18_amd64.AppImage
aee0e0df4c01032b3bd0bd07a16867ac9556dad179a6095bc921f5ff5efee862  OmniVoice Studio_0.3.18_amd64.AppImage.sig
```


### macOS Intel artifacts

```
0f6191a23650030feee045f8aa7290d21b7f3f4689e53f4cbc3ae0ff21c927cc  OmniVoice Studio_0.3.18_x64.dmg
1eef1bba602e593306e1da2d0b4a52e8e8aa5a96c3cce523489611d58aa8deb7  OmniVoice Studio.app.tar.gz
1961333bd38990ccc78ad110e74d6ba5e16161d725fe4e2bed12be3ecb4e4c43  OmniVoice Studio.app.tar.gz.sig
```