[Bug]: Returning from fullscreen Terminal leaves the Android thread sidebar hidden

Area

apps/mobile

Steps to reproduce

1. Launch the mobile app in showcase mode on an unfolded Android foldable, with the thread sidebar visible.
2. Open a thread, then open its Terminal from the thread toolbar.
3. Tap Maximize terminal (the fullscreen button).
4. Tap the top-left toolbar Back button to return to the thread.
5. Observe that the thread sidebar is still hidden and the thread toolbar has no control to restore it.

Expected behavior

Returning from the fullscreen terminal should leave the thread list accessible: either restore the sidebar or provide a visible control to reveal it from the thread screen.

Actual behavior

The conversation occupies the full width after returning. The sidebar, thread search, and sidebar settings/new-task controls are gone. The thread toolbar only offers files, terminal, git, and inspector actions; it has no “Show threads” action.

Impact

Minor bug or occasional failure. This sequence consistently removes access to the thread list from the conversation screen until the user discovers the terminal workaround.

Version or commit

Unmodified main at ccf220be205f0e509021dbc8cbda90daa638e20d.

Environment

• Pixel 9 Pro Fold emulator, unfolded inner display, Android 15 / API 35.
• 2076 × 2152, 390 dpi (approximately 852 × 883 dp).
• Locally built T3 Code Dev with EXPO_PUBLIC_SHOWCASE=1, dark theme, disposable showcase environments.
• Reproduced with the in-app toolbar Back button. Android 17 and iOS were not tested.

Screenshots and recording

Watch the complete reproduction (30-second MP4)

Before opening Terminal	After fullscreen → toolbar Back

Terminal and fullscreen intermediate screenshots. The recording uses only showcase fixtures.

Workaround

Verified: reopen Terminal, tap Show threads, then use the toolbar Back button. The sidebar remains visible on the thread again.

Related work

#5338 covers the broader Android tablet control gaps. This report isolates the terminal fullscreen/back sequence that hides an already-visible sidebar. Open PRs #6521 and #11339 overlap with the missing recovery controls; those branches were not used for this reproduction.

Start in apps/mobile by reproducing the fullscreen Terminal and toolbar Back sequence on the unfolded Android setup described. Trace the return path and sidebar state; the issue names no file or test. Done means the thread list remains accessible after returning, either by restoring the sidebar or providing a visible control, with the sequence verified again.