feat(android): APK versionCode 自动递增 — 每次编译自增，各环境独立计数

参考 rwadurian mobile-app 的 version.properties 方案，为 genex-mobile
和 admin-app 添加 build 时 versionCode 自动 +1 逻辑：

- build.gradle.kts: calculateNextVersionCode() 读取 version.properties，
  自增后写回；versionName 格式 "pubspec版本.buildNumber"（如 1.0.0.42）
- .gitignore: 排除 /android/app/version.properties，每个构建环境
  （本机、CI、服务器）各自维护独立计数器，互不干扰
- 首次编译从 1 开始，后续跨日期持续递增，保证 APK 版本始终唯一

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/admin-app/.gitignore

@@ -44,6 +44,9 @@ app.*.map.json
 /android/app/profile
 /android/app/release
 
+# Auto-generated version code (each build environment maintains its own counter)
+/android/app/version.properties
+
 # Signing keys (do NOT commit to public repos)
 android/key.properties
 android/app/keystore/

frontend/admin-app/android/app/build.gradle.kts

@@ -1,5 +1,6 @@
 import java.util.Properties
 import java.io.FileInputStream
+import java.io.FileOutputStream
 
 plugins {
     id("com.android.application")
@@ -14,6 +15,30 @@ if (keystorePropertiesFile.exists()) {
     keystoreProperties.load(FileInputStream(keystorePropertiesFile))
 }
 
+// ============================================
+// Auto-increment version code on each build
+// ============================================
+val versionPropertiesFile = rootProject.file("app/version.properties")
+val versionProperties = Properties()
+
+fun calculateNextVersionCode(): Int {
+    if (versionPropertiesFile.exists()) {
+        versionProperties.load(FileInputStream(versionPropertiesFile))
+    }
+    val currentCode = versionProperties.getProperty("VERSION_CODE", "0").toInt()
+    val newCode = currentCode + 1
+    versionProperties.setProperty("VERSION_CODE", newCode.toString())
+    versionProperties.store(FileOutputStream(versionPropertiesFile), "Auto-generated version code - DO NOT EDIT MANUALLY")
+    return newCode
+}
+
+val autoVersionCode = calculateNextVersionCode()
+
+fun getAutoVersionName(): String {
+    val flutterVersionName = flutter.versionName
+    return "$flutterVersionName.$autoVersionCode"
+}
+
 android {
     namespace = "cn.gogenex.genex_issuer"
     compileSdk = flutter.compileSdkVersion
@@ -32,8 +57,8 @@ android {
         applicationId = "cn.gogenex.issuer"
         minSdk = flutter.minSdkVersion
         targetSdk = flutter.targetSdkVersion
-        versionCode = flutter.versionCode
-        versionName = flutter.versionName
+        versionCode = autoVersionCode
+        versionName = getAutoVersionName()
     }
 
     signingConfigs {

frontend/genex-mobile/.gitignore

@@ -44,6 +44,9 @@ app.*.map.json
 /android/app/profile
 /android/app/release
 
+# Auto-generated version code (each build environment maintains its own counter)
+/android/app/version.properties
+
 # Signing keys (do NOT commit to public repos)
 android/key.properties
 android/app/keystore/

frontend/genex-mobile/android/app/build.gradle.kts

@@ -1,5 +1,6 @@
 import java.util.Properties
 import java.io.FileInputStream
+import java.io.FileOutputStream
 
 plugins {
     id("com.android.application")
@@ -14,6 +15,30 @@ if (keystorePropertiesFile.exists()) {
     keystoreProperties.load(FileInputStream(keystorePropertiesFile))
 }
 
+// ============================================
+// Auto-increment version code on each build
+// ============================================
+val versionPropertiesFile = rootProject.file("app/version.properties")
+val versionProperties = Properties()
+
+fun calculateNextVersionCode(): Int {
+    if (versionPropertiesFile.exists()) {
+        versionProperties.load(FileInputStream(versionPropertiesFile))
+    }
+    val currentCode = versionProperties.getProperty("VERSION_CODE", "0").toInt()
+    val newCode = currentCode + 1
+    versionProperties.setProperty("VERSION_CODE", newCode.toString())
+    versionProperties.store(FileOutputStream(versionPropertiesFile), "Auto-generated version code - DO NOT EDIT MANUALLY")
+    return newCode
+}
+
+val autoVersionCode = calculateNextVersionCode()
+
+fun getAutoVersionName(): String {
+    val flutterVersionName = flutter.versionName
+    return "$flutterVersionName.$autoVersionCode"
+}
+
 android {
     namespace = "cn.gogenex.genex_consumer"
     compileSdk = flutter.compileSdkVersion
@@ -33,8 +58,8 @@ android {
         applicationId = "cn.gogenex.consumer"
         minSdk = flutter.minSdkVersion
         targetSdk = flutter.targetSdkVersion
-        versionCode = flutter.versionCode
-        versionName = flutter.versionName
+        versionCode = autoVersionCode
+        versionName = getAutoVersionName()
     }
 
     signingConfigs {