App 2.20.0: lease mileage allowance on the Overview

Vehicle info shows the km allowed by today (40,000 km over four years
from 2023-05-01, evenly per day) and the odometer against it.

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

app/build.gradle

@@ -34,8 +34,8 @@ android {
         applicationId "com.stinnesbeck.nilsmg4"
         minSdk 27
         targetSdk 36
-        versionCode 108
-        versionName "2.19.9"
+        versionCode 109
+        versionName "2.20.0"
 
         // Nothing about the server ships in the APK: its URL and ingest token are entered in
         // the app's Server tab (ServerConfig), and the database is only reachable by the server.