Add WordPress integration regressions and automated release checks

[MortenFriisSiteImprove]

Adds WordPress integration regressions and automatic checks for changes to the plugin. Each PR runs two jobs: browser contracts and WordPress single-site/multisite checks. Duplicate branch-push runs are removed, and outdated PR runs are cancelled.

The regression cases cover roles, permissions, URL mapping, settings, content capture, rechecks, and SDK handoff with synthetic fixtures. Experience-selection tests are excluded because that option is being retired. Workflow summaries describe coverage; reports omit Git author metadata, and live diagnostics suppress account data.

Both publishing entry points now require the standard suites, WPCS, protected live integration checks, and a release-ZIP lifecycle check. Create Release publishes the ZIP that passed validation. Live tests use the triggering commit and retain environment approval requirements.

Validation:

• Browser, WordPress environment, and regression suites passed on GitHub against PR64 commit a23af85.
• The live test passed login, Live page data, fresh draft handoff, and loading-state exit against that plugin. The missing-title result assertion is explicitly skipped because the live result mapping remains unverified.
• All 14 local live-runner contract/privacy tests passed; workflow YAML, catalog references, and whitespace checks passed.

Remaining validation:

• The new combined PR jobs must pass on this PR. Results against PR64 do not establish a pass against master; preview-fix coverage may depend on PR64 landing first. This PR does not include its plugin changes.
• The release ZIP lifecycle and reusable release orchestration need their first GitHub execution. The protected environment must allow intended release refs.
• Manual page-report/S2 inspection will verify draft text and styling in the rerender. A passing live smoke test does not establish scan-result correctness.

[MortenFriisSiteImprove]

FYI - the failing tests are expected. When PR64 is merged to master they will run successfully (and show that the bug was fixed).