fix(i18n): disable namespace separator to fix URL display in translations

i18next uses ':' as namespace separator by default, causing URLs like
'https://api.openai.com' to be incorrectly parsed as namespace 'https'
with key '//api.openai.com', resulting in truncated display.

Setting nsSeparator to false fixes this issue since the project doesn't
use multiple namespaces.

web/src/i18n/i18n.js

@@ -42,6 +42,7 @@ i18n
       vi: viTranslation,
     },
     fallbackLng: 'zh',
+    nsSeparator: false,
     interpolation: {
       escapeValue: false,
     },