Show the generate result on the button, with a details modal - #248

After a run, the React admin only showed "Successfully generated 9 items in 12.39s." in small green text below the button, plus a second notice at the top of the page. The 0.9.x screens linked every generated item. This brings that back, and adds more.

On the button

• The status is docked to the Generate button: beside it on wide screens, below the full-width button on narrow ones.
• While it runs: progress and elapsed time.
• When it's done: what was generated, with the right noun ("9 posts generated · 12.4s", thumbnails for media and users on desktop), or the error message. Includes View details and a dismiss button.
• The duplicate notices at the top of each page are gone.

Details modal

• Stats: items, time, per item, requests. A failed run shows the error code and HTTP status instead.
• Every item, with a short summary and edit and view links:
  • posts: status, author, categories, tags
  • media: file type, dimensions, size
  • users: username, role, email
  • terms: taxonomy, slug, parent
  • comments: author, post, status
• Copy IDs, and Open list to the matching admin screen.
• Advanced: full data: every field and meta value of each item, plus the raw request and response of each batch, as JSON with Copy.

REST

• The generate endpoints now return items and list_url, from a new Describes_Generated_Items trait. Documented in the OpenAPI schema.
• User data leaves out the password hash, activation key, capabilities and session tokens.

Fixes found along the way

• REST errors ({ code, message }) showed "An unknown error occurred.". They now show their message.
• Links from batched runs were merged by index, so each batch overwrote the one before.
• Term names came back empty when one wp_get_object_terms() call included post_format, a core quirk. They're now fetched one taxonomy at a time.
• The shadcn Dialog portalled outside the themed React root and sat under the admin bar.

Changelog lines included.

Checked: PHPCS, WPUnit (112 tests, 4 new in GeneratedItemsTest), build, lint, typecheck and Jest (76 tests). On the demo site I clicked through Posts, Users, Terms, Comments and Attachments on desktop and mobile, plus a faked 403. Each click sends one generate request.