* fix(settings): apply already-downloaded models off the GTK main loop
Changing Model Size, Specialization, or Language froze Settings when the
model was already on disk, because reconfigure ran in the changed handler.
Move that apply onto a worker thread (same shape as the download path) and
keep the apply-guard held until GLib.idle_add clears it so a second pick
cannot start a parallel load.
Fixes#789.
* fix(settings): guard Test/apply while downloaded-model worker runs
Block apply_settings and Test Dictation while _applying_settings is held
so a concurrent Test click cannot race the shared engine. Annotate the
new worker/helpers per AGENTS.md and cover the no-op/block behavior.
* fix(settings): resync pickers when a second pick lands mid-apply
While an already-downloaded model worker was running, Model Size /
Specialization / Language could still move. The apply guard blocked
saving the new pick, then finish only cleared the flag, so the UI
could show B with dictation still on A. On finish, if the selection
no longer matches the saved config, put the pickers back. Idle
resyncs from workers now skip a destroyed dialog the same way update
check does.
* fix(settings): always resync pickers after model apply finishes
A second Model Size pick on whisper.cpp could move the size combo
while the apply guard skipped rebuilding specialization, so selected
settings still looked like the saved variant and finish skipped the
resync. Always put the pickers back on the saved config when the
worker ends, and restore language from that config too.
* test(settings): prove mid-apply picker handlers round-trip on finish
Call the real size, specialization, and language handlers while the
apply guard is held, and run finish through the real resync path so
whisper.cpp size and language cannot silently stick on the second pick.
* fix(settings): stop Test Dictation calling a missing model "no speech"
start_recognition now returns whether listening actually began. Test
Dictation checks that before starting its timer, so a missing or
auto-paused model gets a real error instead of "No speech detected".
* fix(settings): reconfigure Test Dictation against the live engine
UI matching config.json is not enough when speech_engine is still on
another engine or model size. Compare those too before the listen timer.
* fix(tests): keep settings_dialog lookups on one module
_load_settings_dialog() restored sys.modules but left
vocalinux.ui.settings_dialog pointing at the private reload.
Python 3.9/3.10 mock follows that attribute, so
test_whisper_list_and_delete patched a different copy than it
imported and the expanduser stub hid the real cache.
Point the package attribute back at the restored module, and
patch the imported module object in the deletion test.
