Improve merge review and branch management for 2.1.1

[hsxk]

Small-release UX, review, privacy, and branch-management improvements built on top of the 2.1 three-way merge model.

Merge review

• Shows readable Base / Original / Branch values for menu order, comment/ping status, and masked post-password state.
• Resolves changed taxonomy term IDs to readable term names.
• Shows featured-image identity and thumbnail previews when available.
• Keeps arbitrary custom-meta values private; only changed keys remain listed.
• Uses WordPress core localization for readable Open / Closed status values.

Branch management

• Existing branch cards show branch ID, creator, modified date/time, state, change count, and conflict count.
• Branch rows identify the original by post ID and, only when readable by the current user, title.
• Adds dedicated Existing branches views to Posts and Pages list tables.
• Keeps list filtering/counts aligned with author capabilities and supports current plus legacy branch relationships.

Security and privacy hardening

• Prevents unreadable private original titles from leaking through branch list states.
• Keeps password values masked in REST review data.
• Keeps arbitrary custom-meta values out of the readable REST comparison.
• Explicitly scopes Existing branches for users without edit_others_posts.

Validation

• Real WordPress integration: 130 / 130 checks.
• Compatibility matrix: WordPress 6.6 / PHP 8.2, WordPress 7.1.1 / PHP 8.2, WordPress 7.1.1 / PHP 8.4.
• Real Gutenberg Chromium E2E: 42 / 42 checks.
• Semantic UI/tutorial contract: 35 / 35 cases.
• PHP 8.2 / 8.3 / 8.4 syntax and WordPress Coding Standards.
• JavaScript/CSS lint, deterministic editor build, deterministic translations, WordPress Plugin Check, and release ZIP audit.
• Release-tree checks exclude development hidden files.

Release metadata is now advanced to 2.1.1. The release tag and WordPress.org deployment will only be created after this release commit passes the complete validation matrix and is merged to master.

[chatgpt-codex-connector]

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