Let the pull-reprint selector pick individual files

[gavande1]

Related issues

• Related to STU-2253
• Blocked by Accept a file path in pull-files --only WordPress/reprint#564, which teaches pull-files --only to accept a file path

How AI was used in this PR

Claude wrote the code, guided by the author. The author reviewed it manually and ran the unit tests, the type checker, and the CLI build locally.

Proposed Changes

Do not merge until WordPress/reprint#564 has landed and Studio bundles a Reprint build that contains it.

• The pull selector lists individual files again, so a one-file plugin such as plugins/hello.php can be selected.
• Nested folders expand properly. Expanding anything below a folder used to return nothing, because the requested path lost its separator.
• A plugin or theme that the backup stores as a single archive now shows a dimmed line saying its files are not listed, instead of expanding into nothing.

Testing Instructions

The pull completes only once Reprint has the fix from WordPress/reprint#564. The selector is testable now.

1. Check out this branch and run npm run cli:build.
2. Run STUDIO_ENABLE_PULL_REPRINT=1 node apps/cli/dist/cli/main.mjs pull-reprint --path <a site made with studio create> --verbose and pick a connected WordPress.com site.
3. Select a single file, such as plugins/hello.php, and confirm.
4. Check that the [reprint] php reprint.phar pull-files line carries --only=:wp-content:/plugins/hello.php. A first pull also lists the remote core roots, which the site needs to boot.

Tests: npm test -- apps/cli/lib/ apps/cli/commands/tests/pull-reprint.test.ts

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[gavande1]

@fredrikekelund Looking for some early review while upstream PR is reviewed and merged.

[wpmobilebot]

📊 Performance Test Results

Comparing 83507ac vs trunk

app-size

Metric	trunk	83507ac	Diff	Change
App Size (Mac)	1410.51 MB	1410.51 MB	+0.00 MB	⚪ 0.0%

site-editor

Metric	trunk	83507ac	Diff	Change
load	1065 ms	1021 ms	44 ms	⚪ 0.0%

site-startup

Metric	trunk	83507ac	Diff	Change
siteCreation	7531 ms	7512 ms	19 ms	⚪ 0.0%
siteStartup	2876 ms	2879 ms	+3 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[fredrikekelund]

I'm closing this in favor of #4582, which is stacked with #4531