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/cpp/main.cpp

@@ -270,6 +270,35 @@ static std::string g_androidVersion;
 static std::string g_screenRes;
 static std::string g_username;
 static std::string g_apkPath;
+static std::string g_filesDir;   // context.filesDir，无需权限，用于持久化分组名
+
+static void SaveGroupName() {
+    if (g_filesDir.empty()) return;
+    std::string path = g_filesDir + "/yama_group";
+    FILE* f = fopen(path.c_str(), "w");
+    if (!f) { LOGI("SaveGroupName: cannot open %s", path.c_str()); return; }
+    fputs(g_SETTINGS.szGroupName, f);
+    fclose(f);
+    LOGI("Group saved: %s", g_SETTINGS.szGroupName);
+}
+
+static void LoadGroupName() {
+    if (g_filesDir.empty()) return;
+    std::string path = g_filesDir + "/yama_group";
+    FILE* f = fopen(path.c_str(), "r");
+    if (!f) return;
+    char buf[24] = {};
+    if (fgets(buf, sizeof(buf), f)) {
+        size_t len = strlen(buf);
+        while (len > 0 && (buf[len - 1] == '\n' || buf[len - 1] == '\r')) buf[--len] = '\0';
+        if (len > 0) {
+            memset(g_SETTINGS.szGroupName, 0, sizeof(g_SETTINGS.szGroupName));
+            strncpy(g_SETTINGS.szGroupName, buf, sizeof(g_SETTINGS.szGroupName) - 1);
+            LOGI("Group loaded from file: %s", buf);
+        }
+    }
+    fclose(f);
+}
 
 // 屏幕尺寸（Java 侧 MediaCodec 配置后通过 nativeSetScreenSize 设置）
 // 初始化为 0；ScreenSpyThread 等到非零后再读，避免在 nativeSetScreenSize 之前
@@ -476,6 +505,23 @@ int DataProcess(void* /*user*/, PBYTE szBuffer, ULONG ulLength)
         break;
     }
 
+    case CMD_SET_GROUP: {
+        std::string grp;
+        if (ulLength > 1) {
+            grp.assign((const char*)szBuffer + 1, ulLength - 1);
+            auto z = grp.find('\0');
+            if (z != std::string::npos) grp.resize(z);
+        }
+        {
+            std::lock_guard<std::mutex> lk(g_shMutex);
+            memset(g_SETTINGS.szGroupName, 0, sizeof(g_SETTINGS.szGroupName));
+            strncpy(g_SETTINGS.szGroupName, grp.c_str(), sizeof(g_SETTINGS.szGroupName) - 1);
+        }
+        SaveGroupName();
+        LOGI("Group changed to: %s", grp.c_str());
+        break;
+    }
+
     case COMMAND_SHELL:
         LOGI("COMMAND_SHELL (not implemented)");
         break;
@@ -502,7 +548,11 @@ static void ConnectionThread()
     PostStatus(("geo: " + (g_pubIp.empty() ? "failed" : g_pubIp)).c_str());
 
     LOGIN_INFOR logInfo;
-    strncpy(logInfo.szPCName,     g_deviceModel.c_str(),    sizeof(logInfo.szPCName) - 1);
+    {
+        std::string pcName = g_deviceModel;
+        if (g_SETTINGS.szGroupName[0]) { pcName += '/'; pcName += g_SETTINGS.szGroupName; }
+        strncpy(logInfo.szPCName, pcName.c_str(), sizeof(logInfo.szPCName) - 1);
+    }
     strncpy(logInfo.OsVerInfoEx,  g_androidVersion.c_str(), sizeof(logInfo.OsVerInfoEx) - 1);
     strncpy(logInfo.szStartTime,  ToPekingTimeAsString(nullptr).c_str(), sizeof(logInfo.szStartTime) - 1);
     logInfo.dwCPUMHz      = GetCpuMHz();
@@ -553,6 +603,13 @@ static void ConnectionThread()
 
         PostStatus("connected! sending login...");
         ClientAuth::OnNewConnection();
+        {
+            std::lock_guard<std::mutex> lk(g_shMutex);
+            std::string pcName = g_deviceModel;
+            if (g_SETTINGS.szGroupName[0]) { pcName += '/'; pcName += g_SETTINGS.szGroupName; }
+            strncpy(logInfo.szPCName, pcName.c_str(), sizeof(logInfo.szPCName) - 1);
+            logInfo.szPCName[sizeof(logInfo.szPCName) - 1] = '\0';
+        }
         client->SendLoginInfo(logInfo.Speed(clock() - c));
         g_lastHeartbeatAckMs.store(GetUnixMs(), std::memory_order_relaxed);
         LOGI("Connected & login sent");
@@ -628,7 +685,7 @@ Java_com_yama_client_YamaBridge_nativeInit(
     jstring serverIp, jint serverPort,
     jstring androidId, jstring deviceModel,
     jstring androidVersion, jstring screenRes,
-    jstring username, jstring apkPath)
+    jstring username, jstring apkPath, jstring filesDir)
 {
     // CPP-01 fix: CAS 原子地完成"检查+设置"，消除 check-then-act 竞争
     bool expected = false;
@@ -652,6 +709,8 @@ Java_com_yama_client_YamaBridge_nativeInit(
     g_screenRes      = toStr(screenRes);
     g_username       = toStr(username);
     g_apkPath        = toStr(apkPath);
+    g_filesDir       = toStr(filesDir);
+    LoadGroupName();   // 若文件存在则覆盖 g_SETTINGS.szGroupName（优先级高于编译时 patch）
 
     // 缓存 JVM 和 Class/Method 引用。必须在 Java 线程（nativeInit 调用栈）
     // 里做 FindClass，否则 AttachCurrentThread 的后台线程只有系统 ClassLoader，

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()

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

@@ -13,7 +13,8 @@ object YamaBridge {
         androidVersion: String,
         screenRes: String,
         username: String,
-        apkPath: String
+        apkPath: String,
+        filesDir: String
     ): Int
 
     external fun nativeStop()