Feat/blueprint demo

[firestar300]

Note

Medium Risk
Adds an MU-plugin that relaxes KSES rules for posts, which can affect content sanitization (though scoped to the Playground/demo environment). The rest is limited to demo content/blueprint restructuring.

Overview
Updates the WordPress Playground blueprint.json to install a small MU plugin that extends wp_kses_allowed_html so the Tabs demo markup retains required accessibility attributes (role, aria-*, tabindex, etc.).

Refactors the demo page creation into a separate runPHP step and replaces the placeholder tab content with a richer, real-world example (Gutenberg-themed tabs) to better showcase the blockparty/tabs block.

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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Generated mu-plugin has literal \t causing PHP fatal error

High Severity

The $lines array uses PHP single-quoted strings containing \t for indentation (e.g. '\tif ( ...'). In PHP single-quoted strings, \t is not interpreted as a tab character — it produces a literal backslash followed by t. When this is written to the mu-plugin file via file_put_contents, the resulting PHP file contains lines starting with \tif, \t\treturn, \t$tags, etc. PHP interprets the backslash as a namespace separator, so \tif(...) becomes a call to undefined function tif(), causing a fatal error that crashes the entire WordPress Playground site on every request.

 

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