fix(newspack-plugin): keep admin list-table Title from collapsing

[jason10lee]

All Submissions:

• Have you followed the Newspack Contributing guidelines?
• Does your code follow the WordPress and VIP Go coding standards? (phpcs clean against the root ruleset)
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

Admin list-table screens (Posts/Pages) render the Title column as an unreadable sliver — text stacking one character per line — once enough columns are visible.

Cause: WP admin list tables use table-layout: fixed, so when many plugins add columns and the declared widths over-subscribe 100%, the width-less Title column is squeezed toward 0px. The width hogs are typically third-party (SEO score/readability, analytics views, consent scan, multi-author) rather than Newspack's own columns — so the fix must be agnostic to which columns trigger it.

This adds Newspack\Admin_List_Table_Layout, which switches Newspack's list-table screens (post/page by default, plus a register_screen() / newspack_admin_autolayout_screens filter surface) to table-layout: auto with a min-width: 35ch floor on the primary column, desktop-scoped (min-width: 783px). Under auto, no column can be starved to 0 regardless of which plugin added it. Screen matching is base-gated (edit vs edit-tags) so the Categories/Tags term screens are untouched.

Closes NPPM-2989

How to test the changes in this Pull Request:

1. On a Posts list with several columns enabled — e.g. an SEO plugin's score/readability columns, an analytics "views" column, a consent "scan" column — open Posts at desktop width (≥783px) and note the Title column collapsing / text stacking vertically.
2. With this change active, reload: the table switches to content-based layout — Title (and every column) stays legible; on extremely crowded screens the table scrolls horizontally instead of collapsing.
3. Confirm the Categories and Tags term screens are unaffected (no layout change).

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes, as applicable? (14 unit tests: screen matching incl. the term-screen leak guard, emission, min-width validation)
• Have you successfully run tests with your changes locally? (14/14 passing; phpcs clean against the root ruleset)

UI-only / non-functional change on a shared admin surface. Verified via multi-model review (design + code) and a live-env A/B (fix on → legible + horizontal scroll on extreme loads; fix off → Title collapses to ~32px). Cross-repo impact review: clean (self-contained to newspack-plugin). Cross-browser: verified in Chromium; Firefox/Safari spot-check pending. Trade-offs: horizontal scroll on extremely crowded screens (strictly better than collapse, and bounded by the Screen Options mitigation support already recommends); mild column-width variation on sparse tables.

[Copilot]

Pull request overview

This PR introduces a small admin-only CSS intervention in newspack-plugin to prevent the Title column in WP admin post/page list tables from collapsing to an unreadable sliver when many extra columns are enabled (typically from third-party plugins). It does this by switching the table to table-layout: auto on targeted screens and enforcing a minimum width for the primary column at desktop breakpoints.

Changes:

• Add Newspack\Admin_List_Table_Layout to emit scoped admin CSS on matching list-table screens.
• Load the new helper from the main Newspack include bootstrap.
• Add unit tests covering screen matching, CSS emission, and min-width validation.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
plugins/newspack-plugin/includes/class-admin-list-table-layout.php	New helper that determines eligible screens and outputs desktop-scoped CSS to keep the primary column readable.
plugins/newspack-plugin/includes/class-newspack.php	Loads the new helper as part of the plugin bootstrap includes.
plugins/newspack-plugin/tests/unit-tests/test-admin-list-table-layout.php	Adds unit tests for screen matching behavior, CSS emission, and min-width filter validation.