Replace the customer app with Doormile CX

Book a pickup, track it to delivery — the rebuilt customer app.

- Design language from doormile-screens.html: brand #8F0F06, Manrope +
  Geist Mono (variable fonts), bordered cards instead of shadows, crimson
  brand headers, sliding tab indicator, mono for anything read digit by digit.
- lib/data (one live API implementation, plus a debug-only offline fake),
  lib/state, lib/ui (tokens, widgets, screens).
- 84 tests, plus a design snapshot harness that renders every screen with the
  real fonts: flutter test test/design_snapshot_test.dart --run-skipped
  --update-goldens

This replaces the previous app (pubspec 'doormile', app id
com.doormile.customer). That tree remains in history at 6c7d656; note its
android/app/google-services.json is not carried over, and the application id
here is in.doormile.customer.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

android/gradle.properties

@@ -1,10 +1,6 @@
-org.gradle.jvmargs=-Xmx2560m -XX:MaxMetaspaceSize=1024m -Dfile.encoding=UTF-8
-org.gradle.parallel=false
-org.gradle.workers.max=1
-org.gradle.daemon=false
+org.gradle.jvmargs=-Xmx8G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError
 android.useAndroidX=true
 # This newDsl flag was added by the Flutter template
 android.newDsl=false
 # This builtInKotlin flag was added by the Flutter template
 android.builtInKotlin=false
-kotlin.incremental=false