* 🐛 Validate plugin UI URLs cannot target Penpot's own domain
The plugin UI iframe combines allow-scripts and allow-same-origin in
its sandbox. While necessary for plugins to use their own cookies and
storage, this creates a risk if a plugin's UI URL resolves to Penpot's
own origin, potentially allowing the iframe to escape sandbox isolation.
Add validateUIUrl() that checks the resolved URL against Penpot's
origin (from penpotPublicURI or location.origin) and throws if they
match. Called in openModal() after prepareUrl() resolves the URL.
Closes#11271
AI-assisted-by: qwen3.7-plus
* 💄 Fix prettier formatting in plugin-manager.spec.ts
Apply prettier formatting to fix format:check failure.
AI-assisted-by: qwen3.7-plus
* 🐛 Fix problem with penpot origin plugins
---------
Co-authored-by: alonso.torres <alonso.torres@kaleidos.net>
