[Components content]: Examples for 2025-01

[SteveSill]

Summary

Adding new example code + descriptions for Admin UI extensions.

Changes

• Adds 3 rich code examples (TS + React TSX) for all 36 admin UI components available in 2025-01, replacing existing placeholder examples
• Each example uses real extension targets (admin.product-details.action.render, block.render), data.selected, close(), query(), and fetch() calls
• Updated all .doc.ts files with action-oriented titles and 2-sentence descriptions explaining WHY + HOW, with links to related components/APIs
• All props validated against 2025-01 TypeScript type definitions

[github-actions]

We detected some changes in packages/*/package.json or packages/*/src, and there are no updates in the .changeset directory. If the changes are user-facing and should cause a version bump, run yarn changeset to track your changes and include them in the next release CHANGELOG. If you are making simple updates to repo configuration, examples, or documentation, you do not need to add a changeset.

[mcvinci]

Approving this one as well! Nice work on improving these examples. ❤️ I noticed that there were a few more file changes in this branch (file deletions), in comparison to the 2025-07 and 2025-04 versions.

Are there any unused example files that we need to clean up across other branches?