AI Assistant: Fix site language parameter on sync AI request

[dhasilva]

Follow-up to #46420

Proposed changes:

• Fixes the casing of the expected language_code body value on sync requests like image caption

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

Does this pull request change what data or activity we track or use?

Testing instructions:

• Send a sync AI request like image caption request
• Check that the request body now has a language_code value instead of languageCode

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack), and enable the fix/jetpack-ai-language-sync branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack fix/jetpack-ai-language-sync

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[github-actions]

Thank you for your PR!

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[Copilot]

Pull request overview

This PR fixes the parameter naming in sync AI requests to use snake_case language_code instead of camelCase languageCode, ensuring consistency with the API expectations and the streaming version of the code.

Key Changes

• Modified the askQuestionSync function to transform languageCode to language_code in the request body
• Added a changelog entry documenting this patch fix

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
projects/js-packages/ai-client/src/ask-question/sync.ts	Adds transformation logic to convert languageCode option to language_code in the request body and removes the camelCase version
projects/js-packages/ai-client/changelog/fix-jetpack-ai-language-sync	Adds changelog entry for the patch fix

[jp-launch-control]

Code Coverage Summary

Coverage changed in 2 files.

File	Coverage	Δ%	Δ Uncovered
projects/packages/jetpack-mu-wpcom/src/features/holiday-snow/class-holiday-snow.php	73/171 (42.69%)	-4.68%	8 💔
projects/js-packages/ai-client/src/ask-question/sync.ts	0/22 (0.00%)	0.00%	1 ❤️‍🩹

Full summary · PHP report · JS report

_{If appropriate, add one of these labels to override the failing coverage check: Covered by non-unit tests Use to ignore the Code coverage requirement check when E2Es or other non-unit tests cover the code Coverage tests to be added later Use to ignore the Code coverage requirement check when tests will be added in a follow-up PR I don't care about code coverage for this PR Use this label to ignore the check for insufficient code coveage.}