cd D:\orisys_ws\orisys-app

git add apps/studio/config/locales/zh_CN.json `
        apps/studio/config/locales/en_US.json `
        apps/studio/tests/test_locales.py `
        apps/studio/tools/ui_check.py `
        apps/studio/tests/test_ui_smoke.py `
        apps/studio/src/orisys_studio/app_window.py `
        apps/studio/src/orisys_studio/ui/cal_panel.py `
        apps/studio/src/orisys_studio/ui/playback_dialog.py `
        apps/studio/src/orisys_studio/ui/force_plots.py `
        apps/studio/docs/record-channel.md `
        shared/src/orisys_app_shared/force/calibration_recorder.py `
        shared/src/orisys_app_shared/record/__init__.py `
        shared/src/orisys_app_shared/record/playback.py `
        shared/src/orisys_app_shared/record/depth.py `
        shared/tests/test_record_channel.py `
        shared/tests/test_playback.py

apps/studio/tests/test_locales.py

@@ -74,3 +74,46 @@ def test_locale_files_are_valid_utf8_json():
         data = _load_locale(name)
         assert isinstance(data, dict)
         assert data.get("app", {}).get("title")
+
+
+#: Sequences that only ever appear when UTF-8 text was decoded as a single-byte
+#: codepage and then re-encoded. A ``Get-Content -Raw | Set-Content`` round trip
+#: in Windows PowerShell does exactly that and silently mangles every non-ASCII
+#: string, which is how the Chinese UI once ended up unreadable.
+#:
+#: Written as escapes, with no literal examples in the comments, so that this
+#: guard cannot itself be corrupted by the same mistake.
+_MOJIBAKE = (
+    "\u00c3",
+    "\u00c2",
+    "\u00e2\u20ac",
+    "\u00e3\u20ac",
+    "\u00ef\u00bf\u00bd",
+)
+
+
+def test_locale_files_are_utf8_without_bom_and_not_mojibake():
+    for name in ("zh_CN", "en_US"):
+        path = LOCALES_DIR / f"{name}.json"
+        raw = path.read_bytes()
+        assert not raw.startswith(b"\xef\xbb\xbf"), f"{name}.json starts with a BOM"
+        text = raw.decode("utf-8")  # raises if it is not valid UTF-8
+
+        for sequence in _MOJIBAKE:
+            assert sequence not in text, (
+                f"{name}.json contains {sequence!r}: the file was decoded with the "
+                "wrong encoding. Rewrite it with an explicit UTF-8 writer instead "
+                "of a PowerShell Get-Content/Set-Content round trip."
+            )
+
+
+def test_chinese_locale_actually_contains_chinese():
+    """A corrupted zh_CN.json still parses as JSON, so check the content."""
+    data = _load_locale("zh_CN")
+    for key in ("menu/theme_dark", "app/about_title", "chart/mode_follow"):
+        node = data
+        for part in key.split("/"):
+            node = node[part]
+        assert any("\u4e00" <= char <= "\u9fff" for char in node), (
+            f"zh_CN.{key} has no Chinese characters: {node!r}"
+        )