Android 0.13, versionCode 15

Both, as always: the code is what tells an existing install a newer
build exists, the name is what a person reads.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app/build.gradle.kts

@@ -40,8 +40,8 @@ android {
         // the paragraph above, so the code keeps climbing and the NAME is what
         // closes the 0.10 -> 0.12 gap. They are allowed to differ: the code is
         // ordering, the name is what a person reads.
-        versionCode = 14
-        versionName = "0.12"
+        versionCode = 15
+        versionName = "0.13"
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }