Administration: Use a unique nonce for Find Posts

[ArkaPrabhaChowdhury]

Trac ticket: https://core.trac.wordpress.org/ticket/43611

The Find Posts modal used the generic _ajax_nonce field name and ID. On post edit screens with the Custom Fields meta box, that produced duplicate #_ajax_nonce elements, so media.js could read the Custom Fields nonce and the Find Posts request would fail with a 403 response.

This gives the Find Posts nonce a dedicated _ajax_nonce-find-posts field and updates the AJAX request to read it while continuing to send the nonce under the _ajax_nonce request key expected by the server.

A regression test verifies that find_posts_div() renders the unique nonce ID and no longer renders id="_ajax_nonce".

Validation:

• phpunit --filter Tests_Admin_IncludesTemplate (43 tests, 125 assertions)
• grunt jshint:core --file=src/js/_enqueues/admin/media.js
• phpcbf src/wp-admin/includes/template.php tests/phpunit/tests/admin/includesTemplate.php
• phpcs src/wp-admin/includes/template.php tests/phpunit/tests/admin/includesTemplate.php

[Copilot]

Pull request overview

This PR fixes a nonce collision in the admin “Find Posts” modal by giving its nonce field a unique DOM ID, preventing media.js from accidentally reading the Custom Fields meta box nonce on post edit screens and causing 403 failures.

Changes:

• Update find_posts_div() to render a dedicated nonce field with id="_ajax_nonce-find-posts".
• Update the Find Posts AJAX request in media.js to read the new nonce field while still sending the nonce under the _ajax_nonce request key expected by check_ajax_referer( 'find-posts' ).
• Add a PHPUnit regression test to ensure the modal renders the unique nonce ID and no longer renders id="_ajax_nonce".

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
tests/phpunit/tests/admin/includesTemplate.php	Adds a regression test asserting the Find Posts modal nonce field uses the unique ID and avoids the generic _ajax_nonce ID.
src/wp-admin/includes/template.php	Changes the Find Posts modal nonce field name/ID to _ajax_nonce-find-posts to eliminate duplicate IDs in the DOM.
src/js/_enqueues/admin/media.js	Updates the Find Posts AJAX logic to read the nonce from #_ajax_nonce-find-posts while continuing to post it as _ajax_nonce.

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[github-actions]

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