opt-in usage notes and a stats dashboard

Release builds ask in setup and Settings whether to send a short note when the app is opened and after each drive: the version, plus the Android version, phone model and cars people tick. Nothing runs in the background. Dev builds always send. The Cloudflare Worker in stats-worker/ stores the notes and serves a private dashboard with GitHub downloads alongside.

gearslip/build.gradle.kts

@@ -35,6 +35,9 @@ android {
         versionCode = 7
         versionName = "0.1.10-alpha"
         manifestPlaceholders["appLabel"] = "Gearslip"
+        // Where opted-in phones send their daily usage note: the stats-worker/ Worker's address,
+        // set as gearslipStatsUrl in gradle.properties. Left empty, nothing is ever sent.
+        buildConfigField("String", "STATS_URL", "\"${project.findProperty("gearslipStatsUrl") ?: ""}\"")
     }
 
     signingConfigs {