On a phone the folder list is the drawer, so it is also where a new folder
is started -- and the New folder dialog was stacked at 900 against the
drawer's 950, so it opened behind the folder list with only a sliver
showing past the drawer's right edge. Unusable: the name field and the
Cancel button were both underneath.
The same trigger, the same fault, one layer down: Compose in the drawer
opens a full-screen composer, and at 800 that came up behind the drawer
too.
A modal has to outrank the navigation that raised it. The dialog backdrop
goes to 960 and the composer dock to 955, which keeps every relationship
those two already had -- a dialog still clears a composer, popovers,
tooltips and toasts still clear both -- and adds the one that was missing.
Desktop is untouched: the drawer's z-index only exists below 768px, and
nothing sat between 800 and 960 anywhere else.
The stack is now written down beside `.dialog-backdrop`, and guarded by a
test on the stylesheet rather than a component test: jsdom has no paint
order, so nothing in a rendered tree can tell that a dialog is behind the
drawer that opened it.
No user-visible strings change; the nine catalogues are untouched, and the
fallback count holds at 16 in each.