Convert the Paging 3 mailbox list + folder drawer to Robolectric JVM Compose
tests (batch 8/9 of umbrella #373) and drop them from jacocoNonJvmTestableSurface.
- MailboxScreenJvmTest drives the real MailboxScreen + MailboxViewModel over
mocked repositories, feeding Paging via static PagingData.from flows (no real
Room/Paging source, mirroring MailboxViewModelTest). Covers the no-accounts
welcome fallback, populated list (sender/subject/snippet, offline badge,
unified per-account labels + filter chips, drafts/outbox entries), the
empty/loading/no-results states, search open/close, and the multi-select
contextual action bar (overflow, archive/spam/delete confirms, move picker,
archive-hidden-in-archive, disambiguated app-bar title).
- FolderDrawerJvmTest drives the callback-driven FolderDrawer: friendly role
names, duplicate-name provider disambiguation + account-switch gap, folder
taps, the multi-account switcher/dropdown, and the unread badge (incl. 99+ cap).
- Remove **/MailboxScreen* and **/FolderDrawer* from jacocoNonJvmTestableSurface;
overall JVM line coverage 84.69% (floor unchanged at 0.79).
The instrumented MailboxScreenTest/FolderDrawerTest stay as the on-device E2E.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>