多语言基础设施：rust-i18n 接入，界面语言默认跟随系统

文案放进 locales/<模块>.yml，经 crate::i18n 的 t! / tn! 取用；启动时先按设置定语言，
改设置时实时切换并发出 UiLocale。守卫测试检查两种语言齐全、占位一致、没有遗漏和死键。
UI 测试夹具固定中文并隔离本线程的语言。共用件（shared/）先转换。

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/ui/support/connection.rs

@@ -12,7 +12,7 @@ pub fn open_workspace_with_tester(
     store: HostStore,
     tester: Arc<FakeConnectionTester>,
 ) -> (WindowHandle<Root>, Entity<Workspace>) {
-    cx.update(shellrs::init);
+    init_app(cx);
     cx.update(|cx| cx.set_reduce_motion(true));
     let mut workspace = None;
     let handle = cx.open_window(size(px(1280.), px(800.)), |window, cx| {
@@ -23,7 +23,7 @@ pub fn open_workspace_with_tester(
         let view = cx.new(|cx| {
             Workspace::new_with_services(
                 store,
-                cx.new(|_| SettingsStore::in_memory()),
+                cx.new(|_| settings_store()),
                 remote,
                 Arc::new(FakeTerminalFactory::default()),
                 Arc::new(FakeSftpProvider::default()),

tests/ui/support/credential.rs

@@ -11,7 +11,7 @@ pub fn open_workspace_with_credentials(
     remote: Arc<RecordingRemoteProvider>,
     tester: Arc<FakeConnectionTester>,
 ) -> (WindowHandle<Root>, Entity<Workspace>) {
-    cx.update(shellrs::init);
+    init_app(cx);
     cx.update(|cx| cx.set_reduce_motion(true));
     let mut workspace = None;
     let handle = cx.open_window(size(px(1280.), px(800.)), |window, cx| {
@@ -19,7 +19,7 @@ pub fn open_workspace_with_credentials(
         let view = cx.new(|cx| {
             Workspace::new_with_services(
                 store,
-                cx.new(|_| SettingsStore::in_memory()),
+                cx.new(|_| settings_store()),
                 remote,
                 Arc::new(FakeTerminalFactory::default()),
                 Arc::new(FakeSftpProvider::default()),

tests/ui/support/forward.rs

@@ -142,7 +142,7 @@ pub fn open_sized_workspace_with_forwards(
     provider: Arc<FakeForwardProvider>,
     window_size: gpui_kit::Size<gpui_kit::Pixels>,
 ) -> (WindowHandle<Root>, Entity<Workspace>) {
-    cx.update(shellrs::init);
+    init_app(cx);
     // The forward dialog's diagram plays a flow over real time, and dialogs
     // slide in: both would move targets between locating and clicking them.
     cx.update(|cx| cx.set_reduce_motion(true));
@@ -155,7 +155,7 @@ pub fn open_sized_workspace_with_forwards(
         let view = cx.new(|cx| {
             Workspace::new_with_services(
                 store,
-                cx.new(|_| SettingsStore::in_memory()),
+                cx.new(|_| settings_store()),
                 remote,
                 Arc::new(FakeTerminalFactory::default()),
                 Arc::new(FakeSftpProvider::default()),

tests/ui/support/mod.rs

@@ -109,6 +109,23 @@ pub fn one_host_store(auth: AuthKind) -> (HostStore, HostId) {
     (store, id)
 }
 
+/// What every fixture starts with: ShellRS's globals, in Chinese, the
+/// language the assertions are written in. The test's interface language is
+/// its own, so one that switches to English switches no other test.
+pub fn init_app(cx: &mut TestAppContext) {
+    shellrs::i18n::isolate_thread();
+    shellrs::i18n::set_locale("zh-CN");
+    cx.update(shellrs::init);
+}
+
+/// Settings kept in memory, in Chinese: by default the interface follows the
+/// system, and CI's is English.
+pub fn settings_store() -> SettingsStore {
+    let mut store = SettingsStore::in_memory();
+    store.update_unnotified(|settings| settings.language = InterfaceLanguage::SimplifiedChinese);
+    store
+}
+
 pub fn appearance_dropdown(window: &mut gpui_kit::Window, item: usize) -> Option<String> {
     window
         .within("settings")

tests/ui/support/sftp.rs

@@ -435,7 +435,7 @@ pub fn open_workspace_with_services(
     provider: Arc<FakeSftpProvider>,
     local: FakeLocalDirectory,
 ) -> (WindowHandle<Root>, Entity<Workspace>) {
-    cx.update(shellrs::init);
+    init_app(cx);
     // Dialogs slide in over real time; small targets such as checkboxes
     // would move between the frame that locates them and the click.
     cx.update(|cx| cx.set_reduce_motion(true));
@@ -448,7 +448,7 @@ pub fn open_workspace_with_services(
         let view = cx.new(|cx| {
             Workspace::new_with_services(
                 store,
-                cx.new(|_| SettingsStore::in_memory()),
+                cx.new(|_| settings_store()),
                 remote,
                 Arc::new(FakeTerminalFactory::default()),
                 provider,

tests/ui/support/terminal.rs

@@ -204,7 +204,7 @@ pub fn open_workspace_with_remote_factory(
     store: HostStore,
     factory: Arc<dyn TerminalTransportFactory>,
 ) -> (WindowHandle<Root>, Entity<Workspace>) {
-    cx.update(shellrs::init);
+    init_app(cx);
     // Dialogs still, as in every fixture: see `open_workspace_with_tester`.
     cx.update(|cx| cx.set_reduce_motion(true));
     let mut workspace = None;
@@ -214,7 +214,7 @@ pub fn open_workspace_with_remote_factory(
         let view = cx.new(|cx| {
             Workspace::new_with_services(
                 store,
-                cx.new(|_| SettingsStore::in_memory()),
+                cx.new(|_| settings_store()),
                 remote,
                 Arc::new(FakeTerminalFactory::default()),
                 Arc::new(FakeSftpProvider::default()),

tests/ui/terminal.rs

@@ -7,7 +7,7 @@ fn open_workspace_with_factory(
     cx: &mut TestAppContext,
     factory: Arc<FakeTerminalFactory>,
 ) -> (WindowHandle<Root>, Entity<Workspace>) {
-    cx.update(shellrs::init);
+    init_app(cx);
     // Dialogs still, as in every fixture: see `open_workspace_with_tester`.
     cx.update(|cx| cx.set_reduce_motion(true));
     let mut workspace = None;
@@ -19,7 +19,7 @@ fn open_workspace_with_factory(
         let view = cx.new(|cx| {
             Workspace::new_with_services(
                 store,
-                cx.new(|_| SettingsStore::in_memory()),
+                cx.new(|_| settings_store()),
                 remote,
                 factory.clone(),
                 Arc::new(FakeSftpProvider::default()),

tests/ui/workspace.rs

@@ -797,7 +797,7 @@ async fn a_dialog_says_what_is_wrong_in_a_notification_that_goes_with_it(cx: &mu
 /// crashed the app at launch.
 #[gpui_kit::test]
 fn a_problem_found_while_the_window_is_built_is_shown_once_it_is_open(cx: &mut TestAppContext) {
-    cx.update(shellrs::init);
+    init_app(cx);
     let handle = cx.open_window(size(px(1280.), px(800.)), |window, cx| {
         let store = cx.new(|_| HostStore::empty());
         let remote = Arc::new(FixedRemoteTerminalTransportProvider::new(Arc::new(
@@ -806,7 +806,7 @@ fn a_problem_found_while_the_window_is_built_is_shown_once_it_is_open(cx: &mut T
         let view = cx.new(|cx| {
             Workspace::new_with_services(
                 store,
-                cx.new(|_| SettingsStore::in_memory()),
+                cx.new(|_| settings_store()),
                 remote,
                 Arc::new(FakeTerminalFactory::default()),
                 Arc::new(FakeSftpProvider::default()),