feat(i18n): complete zh-CN hardening and locale consistency

tests/test_login_locale.py

@@ -0,0 +1,64 @@
+import json
+import urllib.error
+import urllib.request
+
+
+BASE = "http://127.0.0.1:8788"
+
+
+def get(path):
+    with urllib.request.urlopen(BASE + path, timeout=10) as r:
+        return json.loads(r.read()), r.status
+
+
+def get_raw(path):
+    with urllib.request.urlopen(BASE + path, timeout=10) as r:
+        return r.read().decode(), r.status
+
+
+def post(path, body=None):
+    data = json.dumps(body or {}).encode()
+    req = urllib.request.Request(
+        BASE + path, data=data, headers={"Content-Type": "application/json"}
+    )
+    try:
+        with urllib.request.urlopen(req, timeout=10) as r:
+            return json.loads(r.read()), r.status
+    except urllib.error.HTTPError as e:
+        return json.loads(e.read()), e.code
+
+
+def _current_language():
+    settings, status = get("/api/settings")
+    assert status == 200
+    return settings.get("language") or "en"
+
+
+def test_login_page_uses_simplified_chinese_for_zh_cn_alias():
+    prev_lang = _current_language()
+    try:
+        saved, status = post("/api/settings", {"language": "zh-CN"})
+        assert status == 200
+        assert saved.get("language") == "zh-CN"
+        html, status2 = get_raw("/login")
+        assert status2 == 200
+        assert 'lang="zh-CN"' in html
+        assert "\u767b\u5f55" in html
+        assert "\u8f93\u5165\u5bc6\u7801\u7ee7\u7eed\u4f7f\u7528" in html
+    finally:
+        post("/api/settings", {"language": prev_lang})
+
+
+def test_login_page_uses_traditional_chinese_for_zh_hant():
+    prev_lang = _current_language()
+    try:
+        saved, status = post("/api/settings", {"language": "zh-Hant"})
+        assert status == 200
+        assert saved.get("language") == "zh-Hant"
+        html, status2 = get_raw("/login")
+        assert status2 == 200
+        assert 'lang="zh-TW"' in html
+        assert "\u8f38\u5165\u5bc6\u78bc\u7e7c\u7e8c\u4f7f\u7528" in html
+        assert "\u5bc6\u78bc\u932f\u8aa4" in html
+    finally:
+        post("/api/settings", {"language": prev_lang})