feat(myyoast-client): add wp yoast auth reset command and clear-state action

[diedexx]

Context

The MyYoast OAuth client already wipes its full local state (registered client, site/user tokens, key pairs, OIDC/JWKS/DPoP caches) on plugin uninstall via MyYoast_Client_Cleanup::execute(). The same cleanup is useful during development — switching MyYoast environments, recovering from a broken handshake, or letting the Yoast test helper offer a "Clear OAuth state" button — but until now it could only be reached by uninstalling the plugin.

This PR opens two ergonomic entry points on top of that existing service:

1. A public WordPress action wpseo_myyoast_clear_client_state that runs the same cleanup handler.
2. A wp yoast auth reset WP-CLI subcommand alongside the existing wp yoast auth {status,register,verify,deregister,authorize,revoke,rotate-keys} family.

Both reuse MyYoast_Client_Cleanup::execute(), so the CLI command, the dev-tooling action, and the uninstall hook all go through one cleanup path.

Summary

This PR can be summarized in the following changelog entry:

• Adds a wp yoast auth reset WP-CLI command that wipes all MyYoast OAuth client state on the current site.
• Adds an internal wpseo_myyoast_clear_client_state action that triggers the same cleanup without uninstalling the plugin (fired by the test helper plugin).

Relevant technical choices:

• The wpseo_myyoast_clear_client_state action is marked @internal — it exists for Yoast development tooling, not as a long-term public extension point.
• It's an action to decouple the intended use (test helper plugin) from the implementation. The alternative would be to add the reset to the facade, and have a hard dependency on the facade through DI in the test helper.

Test instructions

Test instructions for the acceptance test before the PR gets merged

This PR can be acceptance tested by following these steps:

1. In wp-config.php, add define( 'YOAST_SEO_MYYOAST_CONNECTION', true );.
2. From the plugin folder, run wp yoast auth register to register the site as an OAuth client.
3. Run wp yoast auth status and confirm registered: yes, a client_id, and (optionally) a site/user token.
4. Run wp yoast auth reset — confirm that a prompt appears asking to wipe all MyYoast OAuth client state.
5. Type y to confirm and verify the success message: MyYoast OAuth client state cleared..
6. Run wp yoast auth status again and confirm registered: no, client_id: -, and site_token: none.
7. Repeat from step 2, then run wp yoast auth reset --yes and verify the command runs without a prompt.
8. Repeat from step 2 again. In wp shell (or any PHP context inside WP), run do_action( 'wpseo_myyoast_clear_client_state' ); and verify the same cleanup happens.

Relevant test scenarios

• Changes should be tested with the browser console open
• Changes should be tested on different posts/pages/taxonomies/custom post types/custom taxonomies
• Changes should be tested on different editors (Default Block/Gutenberg/Classic/Elementor/other)
• Changes should be tested on different browsers
• Changes should be tested on multisite

Test instructions for QA when the code is in the RC

• QA should use the same steps as above.

Impact check

This PR affects the following parts of the plugin, which may require extra testing:

• The test hepler's Clear OAuth State button

Other environments

• This PR also affects Shopify. I have added a changelog entry starting with [shopify-seo], added test instructions for Shopify and attached the Shopify label to this PR.
• This PR also affects Yoast SEO for Google Docs. I have added a changelog entry starting with [yoast-doc-extension], added test instructions for Yoast SEO for Google Docs and attached the Google Docs Add-on label to this PR.

Documentation

• [] I have written documentation for this change.

[coveralls]

Coverage Report for CI Build 738408

Warning

Build has drifted: This PR's base is out of sync with its target branch, so coverage data may include unrelated changes.
Quick fix: rebase this PR. Learn more →

Coverage decreased (-0.6%) to 53.342%

Details

• Coverage decreased (-0.6%) from the base build.
• Patch coverage: 5 uncovered changes across 1 file (1 of 6 lines covered, 16.67%).
• No coverage regressions found.

Uncovered Changes

File	Changed	Covered	%
src/myyoast-client/user-interface/auth-command.php	5	0	0.0%

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	67408
Covered Lines:	35851
Line Coverage:	53.19%
Relevant Branches:	16485
Covered Branches:	8899
Branch Coverage:	53.98%
Branches in Coverage %:	Yes
Coverage Strength:	44625.3 hits per line

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💛 - Coveralls

[diedexx]

marking fbr, because the test helper 1.19 depends on this

[pls78]

CR && Acc: ✅