Enter on a webhook in the terminal's Hooks screen opens its last 20 deliveries, each with its state, status and why it failed #7873

The terminal's Hooks screen (src/tui/screens/hooks.ts) shows only each hook's last delivery. When one fails, the admin cannot see whether it always fails or only failed once without opening the web page. That leaves the terminal they work in.

Done:

• [ ] Enter on the selected hook opens a list of its last 20 deliveries from recentDeliveries(db, id, 20), newest first. Each line reads kind · state · HTTP status or reason · attempts, the same words the hooks page uses. With none, it reads No deliveries yet., as the page does. esc/q goes back to the hooks list with the same hook selected.
• [ ] The key is in the screen's bindings (enter, "its deliveries") and shown only to an admin, as the screen is.
• [ ] Never the secret, a payload or a signature.
• [ ] test/tui-hooks.test.ts gains: a hook with an ok and a failed delivery shows both lines with status and reason; a hook with none says No deliveries yet.; esc returns with the same row selected. Each fails without the change.

Files: src/tui/screens/hooks.ts, test/tui-hooks.test.ts. Risks: keep it read-only. Sending a test ping is a separate issue and needs the API first. Builder: scout.