Refine Blueprint selection and creation details

[shaunandrews]

Related issues

• Stacked on Add blueprints library to agentic UI #4701

How AI was used in this PR

AI was used to implement and iteratively refine the user-directed Blueprint gallery and creation flow changes. The resulting diff and automated tests were reviewed locally before pushing.

Proposed Changes

• Present all curated Blueprints in one ordered grid, with development, WordPress.com, and WooCommerce first, and only show search when the collection is large enough to need it.
• Improve gallery readability with opaque card surfaces, three-line descriptions, and subtle thumbnail motion.
• Move Blueprint upload into a secondary header action and align the gallery with the primary site-creation actions.
• Show the selected Blueprint inside the site details panel so people can review its description, plugins, and themes before creating the site.
• Resolve canonical plugin and theme names from WordPress.org, decode directory metadata correctly, and link directory packages to their public pages.

⚠️ Visual change: needs human review in light + dark mode.

Testing Instructions

1. Check out this branch and launch Studio with the agentic UI enabled.
2. Open Add a site and confirm the primary actions and Blueprint grid share the same width and spacing.
3. Confirm the first three Blueprints are Theme & plugin development, WordPress.com, and WooCommerce.
4. Select several Blueprints and confirm the site details panel lists their plugins and themes using readable names without HTML entities.
5. Hover linked WordPress.org packages and confirm the tooltip appears; click one and confirm its directory page opens externally.
6. Check gallery cards, the selected Blueprint panel, and responsive wrapping in both light and dark modes.

Automated checks:

• npm test -- apps/ui/src/components/blueprint-gallery/index.test.tsx apps/ui/src/components/create-site-form/index.test.tsx apps/ui/src/components/blueprint-upload/index.test.tsx apps/ui/src/ui-classic/router/route-onboarding-create/index.test.tsx apps/ui/src/data/queries/use-wordpress-org-package-name.test.ts (39 tests passed)
• npm run typecheck
• ESLint and Prettier on all modified files

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[gavande1]

Thanks @shaunandrews, this looks good to me. I am merging it into #4701 so that everything lands together.