Fix runGit to use ProcessBuilder for AGP 9 compatibility

app/build.gradle.kts

@@ -1,5 +1,3 @@
-import java.io.ByteArrayOutputStream
-
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.compose)
@@ -9,6 +7,14 @@ plugins {
 }
 
 // ── Git-based versioning ────────────────────────────────────
+fun runGit(vararg args: String): String = try {
+    val proc = ProcessBuilder("git", *args)
+        .directory(rootProject.projectDir)
+        .redirectErrorStream(true)
+        .start()
+    proc.inputStream.bufferedReader().readText().trim().also { proc.waitFor() }
+} catch (_: Exception) { "" }
+
 // Version name from latest git tag (e.g. v0.1.0 -> "0.1.0")
 fun gitVersionName(): String = runGit("describe", "--tags", "--abbrev=0")
     .removePrefix("v")
@@ -23,23 +29,8 @@ fun buildNumber(): Int {
 fun gitShortHash(): String = runGit("rev-parse", "--short", "HEAD")
     .ifEmpty { "unknown" }
 
-// Display: "0.1.0+6.abc1234"
-fun gitDisplayVersion(): String {
-    val base = gitVersionName()
-    val build = buildNumber()
-    val hash = gitShortHash()
-    return "$base+$build.$hash"
-}
-
-fun runGit(vararg args: String): String = try {
-    val out = ByteArrayOutputStream()
-    project.exec {
-        commandLine("git", *args)
-        standardOutput = out
-        isIgnoreExitValue = true
-    }
-    out.toString().trim()
-} catch (_: Exception) { "" }
+// Display: "0.1.0+7.abc1234"
+fun gitDisplayVersion(): String = "${gitVersionName()}+${buildNumber()}.${gitShortHash()}"
 
 // ─────────────────────────────────────────────────────────────