Apply queue entries selectively, and ignore them permanently

Problem/Motivation

Applying everything at once is not how a site with a live front end works: some changes are wanted now, some later, some never. And an entry that is rejected must stay rejected, or every scan re-proposes the same thing until people stop reading the list.

Proposed resolution

• Apply selected entries: update the model configuration, regenerate the affected files, rebuild the plugin and route caches.
• Apply all, with the breaking entries listed separately in the confirmation.
• Ignore: the field is recorded as not part of the API and is never proposed again, with a way to see and undo the ignore list.
• Applying is transactional per entry — a failed regeneration must not leave the configuration updated and the files stale.

Remaining tasks

Everything.