liveness(webhook): label and description are live on the Studio metadata list

The 2026-10-19 dead verdict measured the Setup sys_webhook list only. The
Studio metadata list (objectui ResourceListPage defaultColumns) and the
metadata quick-find read the declared registry item over
GET /api/v1/meta/webhook, which a booted examples/app-showcase serves with
the authored label and description. Re-graded under the designer-previews
ruling, on the hook.label and email_template.label precedent; counts shard
regenerated.

Claude-Session: https://claude.ai/code/session_01D6F9axfoPzR7t8G1J7Ytzz
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/spec/liveness/state-counts/webhook.md

@@ -12,4 +12,4 @@ committed anywhere: `check:liveness` sums the shards when it reads them.
 
 | Type | live | exp | elsewhere | dead | planned | classified |
 |---|---|---|---|---|---|---|
-| `webhook` | 17 | 0 | 0 | 2 | 0 | 19 |
+| `webhook` | 19 | 0 | 0 | 0 | 0 | 19 |