Release: Emulsify Wordpress 2.0

[callinmullaney]

This PR does the following:

• Prepares Emulsify Wordpress 2.0 as a stable Timber-first WordPress parent theme release
• Replaces the old unsupported 1.x starter-theme model with a parent theme plus generated child theme architecture
• Updates the project for WordPress 6.7+, PHP 8.3+, Timber 2, Node 24, Emulsify Core 4, Vite, Storybook, and Twig
• Adds a bundled Whisk child theme starter with project.emulsify.json configured for platform: "wordpress"
• Adds WP-CLI child theme generation through wp emulsify, including dry-run, force, machine-name, and activation support
• Moves reusable WordPress runtime behavior into namespaced classes under includes/
• Adds parent theme bootstrapping, setup, asset loading, Timber integration, Twig namespaces, Twig helpers, context handling, and missing-Timber handling
• Adds child-first asset loading from built dist/global and dist/components output
• Adds Core-style Twig helpers such as bem() and add_attributes()
• Adds project-machine-name component include support, while preserving legacy @components compatibility
• Adds optional ACF Local JSON path integration for child themes
• Adds optional ACF/Twig block registration from component metadata
• Adds optional native Gutenberg block registration from built block.json files
• Adds JSON block pattern registration support
• Adds editor enhancement and editor policy services for project-owned editor behavior
• Adds release readiness, PR validation, smoke checks, semantic-release workflow support, and WordPress theme readiness CI
• Adds documentation for upgrading, parent/child architecture, Core 4/Vite workflow, Timber/Twig authoring, block integrations, editor features, asset loading, WP-CLI generation, release process, and sister-project parity
• Removes legacy Webpack, Storybook 6, Travis, old component examples, and outdated 1.x tooling/configuration

Related Issue(s)

• N/A

Notes:

• This is a major release branch and should be treated as a breaking change from the old 1.x starter-theme model.
• The intended model is: emulsify is the reusable parent runtime, and generated child themes own project components, templates, Sass, JavaScript, built assets, and site-specific overrides.
• The bundled whisk/ directory is the child theme starter source. Generated projects should activate the child theme, not the parent theme.
• The standalone Emulsify CLI starter is expected to represent the generated child theme layer from whisk/, not the parent runtime theme root.
• Current CI status: WordPress Theme Readiness is passing. The PR run completed the practical readiness job successfully; the full WordPress fixture and extended Whisk Storybook/a11y jobs are intentionally skipped on normal PR runs.

Functional Testing:

• Run npm ci --ignore-scripts.
• Run composer validate --no-check-publish --strict.
• Run npm audit --omit=dev.
• Run npm audit.
• Run npm run lint:php.
• Run npm run pr:check.
• Run npm run release:check.
• Run npm run publish-test -- --no-ci to confirm the semantic-release dry run targets 2.0.0.
• In a WordPress install with WP-CLI available, test wp emulsify "Acme Site" --dry-run.
• Generate a child theme with wp emulsify "Acme Site" --machine-name=acme-site.
• Confirm the generated child theme has updated theme headers, package metadata, project.emulsify.json, and Template: emulsify.
• Activate the generated child theme and confirm the parent theme runtime loads through Timber.
• From the generated child theme, run npm install.
• From the generated child theme, run npm run build after installing/configuring a component system with Vite input files.
• Review the new docs for upgrade guidance, parent/child responsibilities, Core 4 workflow, block integrations, and release process.