The dashboard's main column is `relative z-2` (App.tsx), which creates a
stacking context that traps fixed descendants below the app sidebar
(`z-50`). `ModelPickerDialog` renders `fixed inset-0 z-[100]` inline,
so its z-100 is scoped to z-2 and the sidebar covers its left edge.
The bug is visible across all themes but only obvious in the Large theme
variants (Hermes Teal (Large), etc.) where the larger root font widens
the dialog into the sidebar's column. Toast.tsx already documents the
same trap and uses the same `createPortal(..., document.body)` escape.
This commit ports the picker; the same pattern affects other inline
z-[100] modals in the dashboard (OAuthLoginModal, Cron / Models /
Profiles page modals) and is left for a follow-up — keeping this PR
scoped to the reporter's specific case.
Fixes#28103
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
c5cafd3847