feat: add Traditional Chinese (zh-TW) locale

Add Traditional Chinese (Taiwan) translation as a new locale.

The translation is derived from the existing Simplified Chinese (zh)
locale and converted using OpenCC (s2twp configuration) to produce
Taiwan-specific Traditional Chinese, including vocabulary differences
such as 軟體 (software), 資料 (data), 社群 (community), and
使用者 (user).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/client/project.json

@@ -53,6 +53,10 @@
       "zh": {
         "baseHref": "/zh/",
         "translation": "apps/client/src/locales/messages.zh.xlf"
+      },
+      "zh-TW": {
+        "baseHref": "/zh-TW/",
+        "translation": "apps/client/src/locales/messages.zh-TW.xlf"
       }
     },
     "sourceLocale": "en"
@@ -284,6 +288,7 @@
           "messages.pt.xlf",
           "messages.tr.xlf",
           "messages.uk.xlf",
+          "messages.zh-TW.xlf",
           "messages.zh.xlf"
         ],
         "trim": true