Feat: Android client device grouping with persistent group name

- szPCName sent as "model/groupName" format matching Linux client
- CMD_SET_GROUP handler updates g_SETTINGS.szGroupName in memory
- Group name persisted to filesDir/yama_group; survives process restart
- LoadGroupName() at startup overrides build-time patch value if file exists

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

android/app/src/main/java/com/yama/client/CaptureService.kt

@@ -143,7 +143,7 @@ class CaptureService : Service() {
         // ExceptionInInitializerError 包裹 UnsatisfiedLinkError（首次访问 object 时触发）
         val initRet: Int
         try {
-            initRet = YamaBridge.nativeInit(ip, port, androidId, model, osVer, res, user, packageCodePath ?: "")
+            initRet = YamaBridge.nativeInit(ip, port, androidId, model, osVer, res, user, packageCodePath ?: "", filesDir.absolutePath)
         } catch (e: UnsatisfiedLinkError) {
             Log.e(TAG, "Native library load failed: $e")
             stopSelf()