* fix(settings): stage Advanced model spec until Download is confirmed
Picker changes in Speech Model -> Advanced staged a spec but immediately triggered a model download for every intermediate selection. Gate the auto-apply download path so a missing model only stages: a Download action on the model info card now runs apply_settings() as the single explicit confirmation. Simple-mode questions keep the instant apply-and-download flow.
Fixes#894
* fix(settings): repaint model info card after a completed download
The post-download paths repopulated pickers and resynced the engine but never repainted the info card, so a finished download left the amber status and the Download action visible for a model already on disk. The cancel path already repainted via the idle resync; give success its own.
* fix(settings): keep staged spec through picker rebuilds and save non-model edits
* fix(settings): persist non-model edits without a model-reloading reconfigure
* fix(settings): live-apply non-model edits, keep whispercpp params saved-only while staged
* fix(settings): live-set changed VAD/timeout attrs without reconfigure while staged
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Co-authored-by: Jatin K Malik <jatinkrmalik@gmail.com>
