i18n(showcase): translate the new multi-value lookup label

The f_lookups field added to the field zoo declared an English label with
no zh-CN counterpart, tripping the i18n coverage ratchet (456 -> 457
untranslated declared strings). Translate it so the new string does not
widen the baseline.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Gusro3gdGv4wgbBnaFy9ah

Author: claude

examples/app-showcase/src/system/translations/index.ts

@@ -266,6 +266,7 @@ export const ShowcaseTranslationBundle = {
       },
       showcase_field_zoo: {
         label: '字段动物园', pluralLabel: '字段动物园',
+        fields: { f_lookups: { label: '查找 → 客户（多值）' } },
       },
     },
   },