chore(versioning): derive Android versionName from git describe to match __APP_VERSION__ from vite

android/app/build.gradle

@@ -1,8 +1,29 @@
 apply plugin: 'com.android.application'
 
-def packageJson = new groovy.json.JsonSlurper().parseText(file('../../package.json').text)
-def semver = packageJson.version.split('\\.')
-def computedVersionCode = semver[0].toInteger() * 1000000 + semver[1].toInteger() * 1000 + semver[2].toInteger()
+// Mirror of resolveAppVersion() in ../../vite.config.js so the APK's
+// versionName matches __APP_VERSION__ rendered in the About screen.
+// `git describe --tags --match 'v*'` against tag v0.2.0 yields
+// `v0.2.0-<commits>-g<hash>`; patch = commit count since the tag.
+// Falls back to package.json only when git is unavailable.
+def gitDescribe = providers.exec {
+    it.commandLine 'git', 'describe', '--tags', '--match', 'v*', '--always'
+    it.workingDir rootDir.parentFile
+    it.ignoreExitValue = true
+}
+def appVersion = {
+    def fromGit = gitDescribe.result.get().exitValue == 0 ? gitDescribe.standardOutput.asText.get().trim() : null
+    def m = fromGit =~ /^v?(\d+)\.(\d+)\.(\d+)(?:-(\d+)-g[0-9a-f]+)?$/
+    if (fromGit && m.matches()) {
+        def major = m[0][1].toInteger()
+        def minor = m[0][2].toInteger()
+        def patch = (m[0][4] ?: m[0][3]).toInteger()
+        return [name: "${major}.${minor}.${patch}", major: major, minor: minor, patch: patch]
+    }
+    def pkg = new groovy.json.JsonSlurper().parseText(file('../../package.json').text)
+    def parts = pkg.version.split('\\.')
+    return [name: pkg.version, major: parts[0].toInteger(), minor: parts[1].toInteger(), patch: parts[2].toInteger()]
+}()
+def computedVersionCode = appVersion.major * 1000000 + appVersion.minor * 1000 + appVersion.patch
 
 android {
     namespace = "chat.vojo.app"
@@ -12,7 +33,7 @@ android {
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
         versionCode computedVersionCode
-        versionName packageJson.version
+        versionName appVersion.name
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         aaptOptions {
              // Files and dirs to omit from the packaged assets dir, modified to accommodate modern web apps.

docs/ai/android.md

@@ -26,7 +26,7 @@ npm run android:apk:debug      # gradle debug build only
 
 ## Versioning
 
-`versionCode` and `versionName` auto-derived from `package.json` version:
+`versionCode` and `versionName` are derived from `git describe --tags --match 'v*'` in [`android/app/build.gradle`](../../android/app/build.gradle), mirroring `resolveAppVersion()` in [`vite.config.js`](../../vite.config.js) so the APK's `versionName` matches `__APP_VERSION__` shown in About. Tag is `v0.2.0`; `patch` is the commit count since that tag (e.g. `v0.2.0-87-g…` → versionName `0.2.87`). When git is unavailable, falls back to `package.json` `version`.
 
 ```
 versionCode = major * 1_000_000 + minor * 1_000 + patch

package.json

@@ -1,7 +1,7 @@
 {
   "name": "vojo",
-  "version": "4.11.1",
-  "description": "Yet another matrix client",
+  "version": "0.2.0",
+  "description": "Vojo client for matrix server",
   "main": "index.js",
   "type": "module",
   "engines": {