i18n(showcase): translate the new inline picker param (#3405)

`check-i18n-coverage` ratchets each example at its current untranslated count,
so a newly declared label that skips a locale the example claims to support
pushes the count up and fails the gate — 456 → 460 here (`p_assignee`'s `label`
and `helpText`, each counted on two surfaces).

Translated rather than ratcheting the baseline up: ratcheting is what the gate
exists to prevent, and the script only sanctions `--update` for a count that
went DOWN. The gallery's older params sit inside the 456 baseline; this one is
not allowed to widen it.

`负责人` is what the bundle already renders for `showcase_task.assignee`, so the
same idea keeps one word. The flow specimen's own label/description are not
flagged — the `i18n/missing-action` rule covers action params, not flow nodes.

`check-i18n-coverage` now reports "none new"; validate, typecheck and the 58
example tests all pass.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LkvDs4y4gveyB5NJZKxaZt

Author: claude

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

@@ -267,6 +267,23 @@ 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）' } },
+        // #3405 — the inline system-object picker specimen. Translated at birth
+        // because `check-i18n-coverage` ratchets this example at its current
+        // untranslated count: a newly declared label that skips zh-CN pushes the
+        // count up and fails the gate. (The gallery's older params sit inside
+        // that baseline; this one is not allowed to widen it.) `负责人` matches
+        // what the bundle already renders for `showcase_task.assignee`, rather
+        // than introducing a second word for the same idea.
+        _actions: {
+          showcase_action_param_gallery: {
+            params: {
+              p_assignee: {
+                label: '负责人',
+                helpText: '指向系统对象的内联查找 —— 可按姓名或邮箱搜索,无需填写 UUID。',
+              },
+            },
+          },
+        },
       },
     },
   },