Fix: Decode GBK dialog/toolbar text on non-Chinese systems

MBCS dialog templates are decoded with the system ANSI code page, so on
non-Chinese systems the GBK template strings turn into "?" before
TranslateDialog can read them. Set those strings explicitly in OnInitDialog
(PluginSettings save/close, the three Advanced dialogs, the file-manager
search buttons/checkboxes, and Trigger Settings) so they are re-decoded
with the thread locale. Also fix the language-selection dialog and the
toolbar "Lang/语言" button: the language dialog's template is built as
WCHAR strings but created through the ANSI path, so its title, label, and
buttons are set explicitly in OnInitDialog (AppendString stays on CP_ACP),
with the title looked up via _TR("切换语言") and set through SetWindowTextW
after an explicit GBK conversion; new en_US ("Switch Language") and zh_TW
("切換語言") translations accompany it. The toolbar button is set through
the Unicode TB_SETBUTTONINFOW message after an explicit GBK conversion. Add
en_US/zh_TW translations for the experimental-features context menu items.

Co-Authored-By: deepseek-v4-pro

server/2015Remote/LangManager.h

@@ -723,11 +723,11 @@ protected:
         AppendData(&dlgTemplate, sizeof(DLGTEMPLATE));
         AppendWord(0);  // 菜单
         AppendWord(0);  // 窗口类
-        AppendString(_T("切换语言 / Switch Language"));
+        AppendString(_T("切换语言"));
         AlignToDword();
 
         // 静态文本
-        AddControl(0x0082, 15, 15, 50, 12, (WORD)-1,
+        AddControl(0x0082, 15, 15, 50, 12, 1002,
                    SS_LEFT | WS_CHILD | WS_VISIBLE, _T("语言:"));
 
         // ComboBox
@@ -796,8 +796,17 @@ protected:
     {
         CDialog::OnInitDialog();
 
-        // 翻译对话框控件（标题、标签、按钮）
-        TranslateDialog(this);
+        // 模板为动态构造的 Unicode 模板，MBCS 下被 ANSI 创建路径误读，标题/标签/按钮文字会乱码，
+        // 故在此显式设置（走线程 locale GBK，与其它对话框同法），不再对已乱码文本调用 TranslateDialog。
+        // 标题含中文：非中文系统上 ANSI 消息按系统 ACP 解码会乱码，用 _TR 取翻译（中文→切换语言，
+        // 英语→Switch Language）后，显式 GBK(936)→Unicode 转换再用 Unicode 消息设置（与工具栏同法）。
+        CString strTitle = _TR("切换语言");
+        WCHAR wTitle[64] = { 0 };
+        MultiByteToWideChar(936, 0, strTitle, -1, wTitle, 64);
+        ::SetWindowTextW(m_hWnd, wTitle);
+        SetDlgItemText(1002,     _TR("语言:"));
+        SetDlgItemText(IDOK,     _TR("确定"));
+        SetDlgItemText(IDCANCEL, _TR("取消"));
 
         m_comboLang.SubclassDlgItem(1001, this);