Content Resizing: Preserve inline HTML

[yogeshbhutkar]

What, Why, and How?

This PR enables preserving inline HTML in content resizing, ensuring links, emphasis, code, and other inline formatting survive the AI transformation.

The documentation and system prompts indicate that the experiment preserves inline HTML; however, this did not happen because the toolbar used the getBlockText helper. This PR replaces it with the shared getBlockHTML utility so formatted content is sent to the content-resizing ability with its inline markup intact.

Ref:

ai/docs/experiments/content-resizing.md

Line 5 in 5599e9d

The Content Resizing experiment lets editors transform the content of an individual block in three ways — **Shorten**, **Expand**, or **Rephrase** — directly from the block toolbar. The experiment registers a WordPress Ability (`ai/content-resizing`) that returns the transformed text while preserving inline HTML (links, emphasis, code, etc.). The ability can be called both through the in-editor UI and directly via REST API for automation.

Use of AI Tools

AI assistance: Yes
Tool(s): Codex
Model(s): GPT-5.6 Sol
Used for: Code review

Testing Instructions

1. Enable the Content Resizing experiment and configure an AI provider.
2. Create a post with a paragraph containing inline formatting, such as a link, bold, italic, and inline code.
3. Select the paragraph and choose Resize Content → Rephrase.
4. Verify the original and suggested content retain the inline formatting.
5. Accept the suggestion and confirm the formatting remains intact in the editor and after saving/reloading the post.

Screencast

Before

before-bug.mov

After

after-fix.mov

Changelog Entry

Fixed - Preserve inline HTML when resizing content.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.43%. Comparing base (5599e9d) to head (ffbf4b4).

Additional details and impacted files

@@            Coverage Diff             @@
##             develop     #915   +/-   ##
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  Coverage      80.43%   80.43%           
  Complexity      2565     2565           
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  Files            110      110           
  Lines          10448    10448           
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  Hits            8404     8404           
  Misses          2044     2044           

Flag	Coverage Δ
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