App 2.16.3: full screen stays with drop-downs and dialogs

Opening a drop-down or a dialog brought the car's bars back until it
closed: each is a window of its own, and the system shows the bars when
a window without the full-screen flags takes focus.

- The drop-downs (upload frequency, tyre pressure unit, accent colour)
  are now single-choice buttons on the page: no extra window, one tap
  instead of two, full touch targets, the choice in the accent colour.
- Dialogs (About, update, pairing, phone settings, trip reset, date
  picker) are shown unfocusable, given the activity's full-screen
  flags, and only then allowed focus. None of them takes typing, which
  an unfocusable window would block.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QLJfZQZeAKAwSqViTmLzki

SPECS.md

@@ -112,6 +112,11 @@ tyre pressures, GPS (lat, lon, elevation, heading) and the is_* flags. It does *
   INGEST_TOKEN) into git and pushed it. Commit amended and force-pushed; both values regenerated in
   the now gitignored `k8s/secrets.yaml` (since moved to `k8s/secrets/secrets.yaml`, outside
   `kubectl apply -f k8s/`). Filled-in secrets live only there from now on.
+- 2026-10-18 — App 2.16.3: full screen stays while choosing or reading a dialog. Drop-downs (upload
+  frequency, tyre unit, accent colour) are now buttons on the page: a drop-down is a window of its
+  own without the full-screen flags, so the car showed its bars while it was open. Dialogs are
+  shown unfocusable, given the activity's full-screen flags, then allowed focus
+  (`showKeepingFullScreen`); none of them takes typing.
 - 2026-10-18 — From the car (2.16.2): screen 1920×720 px at 160 dpi with a 1778×720 px app
   window, so EVProfile's 1280×480 does not apply; colour probe found only `vehicle_type = AS28`.
   FIRMWARE.md, mise.toml and SPECS.md say so.