App 2.16.2: show the car's screen size; display figures documented

The MG4's display is given as 1920x720 (this project), 1280x480
(EVProfile's README) and a 1778x720 app window (upstream). 1280x480 is
exactly 1920x720 px at 240 dpi expressed in dp, so the figures may
describe one panel at different densities, which this platform lets be
changed per app.

The Logs tab's new SCREEN line shows the panel's pixels and density and
the app window in px and dp, to settle it from the car. FIRMWARE.md
lists the three figures and what the emulator shows at 240 dpi;
mise.toml, README and SPECS.md no longer state 160 dpi as fact for the
car.

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

app/src/main/res/values/strings.xml

@@ -40,6 +40,8 @@
     <string name="power_waiting">needs a minute of data</string>
     <string name="label_tire_unit">Tyre pressure unit</string>
     <string name="label_accent">Accent colour</string>
+    <string name="label_screen">SCREEN</string>
+    <string name="screen_info">Panel %1$d × %2$d px at %3$d dpi\nApp window %4$d × %5$d px = %6$d × %7$d dp</string>
     <string name="label_car_color">CAR COLOUR</string>
     <string name="hint_car_color">Lists the head unit\'s settings that mention a colour, paint or car model, to find out whether the car\'s colour can be read. A photo of this list helps.</string>
     <string name="btn_car_color">Look for the car colour</string>