Add Capacitor Android project and native Tiptoi plugin

Checked-in android/ Capacitor project plus the native TiptoiPlugin
(Kotlin): SAF directory picker for the pen, listing/copying/deleting
.gme files on the pen, and downloading GME/cover files into
app-private storage.

client/android/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.11.1-all.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists