App 2.34.1: a tab to leave the Overview's full screen beside the car's sidebar

Without the app's own full screen, the car's sidebar takes the left edge
and a swipe from there never reaches the app. A small tab at the app's
left edge now brings the navigation back, by a tap or a swipe from it.
In the app's full screen the handle and edge swipe stay as they were.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

SPECS.md

@@ -138,6 +138,15 @@ tyre pressures, GPS (lat, lon, elevation, heading) and the is_* flags. It does *
   confirmed car facts, app structure, UI conventions, build/test/ship, documents. It replaces
   upstream's EVABRPUploader text. The test emulator is now in the flake: `nix run .#car-emulator`
   (Android 9 AOSP at 1920×720, 160 dpi; the car build installs as the system user — checked).
+- 2026-10-25 — App 2.34.1 (branch `styles-retro-future`): the Overview's full screen without the
+  app's full screen. With the car's bars shown, the car's own sidebar sits at the left edge, so a
+  swipe from the edge lands on it, not on the app (owner, on the car). There a small tab now sits
+  at the app's left edge instead of the faint handle (48 × 96 dp touch area, a dark tongue with
+  ›): a tap brings the navigation back, and so does a swipe starting in the app's first 56 dp
+  (`tabSwipe`). In the app's full screen nothing changed (handle and edge swipe, the owner's
+  preference: least clutter). Switching Full screen on Settings updates it at once. Emulator:
+  the tab shows, a tap and a swipe on the left strip both bring the navigation back. Not tried
+  on the car.
 - 2026-10-25 — App 2.34.0 (branch `styles-retro-future`): **drive mode at start.** The car falls
   back to its own default mode when switched on; with "Set at start" (on by default, the switch
   in the drive mode card) the app sets the mode last chosen on Settings again. Only a choice the