Show a real version name on Android builds instead of the run number

The rolling APK workflow passed the CI run number as both versionCode
and versionName, so the app reported its version as "117". Keep the
increasing code as CI's job, but compose the user-visible name in
gradle from a single base version: rolling builds now show
"0.1.1 (build N)" so testers can still report the exact build.

Also treat blank ANDROID_VERSION_CODE/NAME env vars as absent: the
release workflow forwards optional inputs verbatim, so a blank input
used to produce an empty versionName (and a NumberFormatException on
the code) instead of falling back to the gradle default.

Author: zo-sol

.github/workflows/android-apk.yml

@@ -154,8 +154,9 @@ jobs:
           # Keep the rolling sideload APK installable over previous team builds. Without this,
           # debug builds fall back to versionCode 1 and Android refuses to update any tester
           # who already has a newer local or Play-signed build installed.
+          # versionName is composed in build.gradle.kts ("0.1.1 (build N)"); only the
+          # strictly increasing code is CI's job.
           ANDROID_VERSION_CODE: ${{ github.run_number }}
-          ANDROID_VERSION_NAME: ${{ github.run_number }}
         run: ./gradlew --no-daemon assembleDebug
 
       # SHA-1 is a public fingerprint (not the key), safe to log — proves the team key signed it.

surfaces/android/app/build.gradle.kts

@@ -42,10 +42,18 @@ android {
         targetSdk = 35
         // Play requires a strictly increasing versionCode for every upload to a track. CI passes
         // the next number via ANDROID_VERSION_CODE; local/debug builds fall back to 1 unchanged.
-        versionCode = (providers.environmentVariable("ANDROID_VERSION_CODE").orNull
-            ?: localProperties.getProperty("versionCode"))?.toInt() ?: 1
-        versionName = providers.environmentVariable("ANDROID_VERSION_NAME").orNull
-            ?: localProperties.getProperty("versionName", "0.1.0")
+        // Workflows pass optional inputs straight through as env vars, so a blank input
+        // arrives as an empty string, not an unset var; treat blank as absent or the
+        // release workflow's "blank = keep gradle default" promise silently breaks.
+        val ciBuild = providers.environmentVariable("ANDROID_VERSION_CODE").orNull?.takeIf { it.isNotBlank() }
+        versionCode = (ciBuild ?: localProperties.getProperty("versionCode"))?.toInt() ?: 1
+        // The marketing version lives HERE (single source); the release workflow can still
+        // override it via ANDROID_VERSION_NAME. Rolling CI builds append their run number so
+        // testers can report exactly which build they have ("0.1.1 (build 117)"), instead of
+        // the old behavior of showing the bare run number as the whole version.
+        val baseVersion = localProperties.getProperty("versionName", "0.1.1")
+        versionName = providers.environmentVariable("ANDROID_VERSION_NAME").orNull?.takeIf { it.isNotBlank() }
+            ?: if (ciBuild != null) "$baseVersion (build $ciBuild)" else baseVersion
         buildConfigField(
             "String",
             "GOOGLE_OAUTH_CLIENT_ID",