enhancement(model picker): group starred models across providers and commit a selection on dismissal #9

Problem

The new-thread model picker did not show all starred models together at the top regardless of provider, and on mobile a swipe-dismiss discarded the staged selection while only Done applied it. Desired: starred models grouped across providers; a selection is kept on Done or dismiss; only Cancel reverts.

What the code shows

Mobile ThreadSettingsSheet staged pendingModel, committed only on Save/Done, and had no dismiss handler, so a gesture dismissal dropped it silently. Favorites were grouped per provider only.

Proposed fixes

Landed on fix/model-picker-selection (merged, release 7345a87552): a global Favorites section above the provider list on mobile; dismissal commits the staged model; only Cancel reverts; the web commit path is hardened so an unavailable row cannot commit.

Related

#2. Branch fix/model-picker-selection.

Severity: Low (UX).