Add support for Blueprints defineSiteUrl

[bcotrim]

Related issues

• Fixes https://linear.app/a8c/issue/STU-830

Proposed Changes

• Extract defineSiteUrl from blueprint steps to pre-populate the custom domain field
• Create bidirectional mapping utilities between blueprint settings and form values (extractFormValuesFromBlueprint / updateBlueprintWithFormValues)
• Add BlueprintSiteSettings type for shared settings between blueprints and forms
• Pre-populate custom domain from defineSiteUrl step and expand advanced settings
• Pre-populate HTTPS toggle based on the protocol in defineSiteUrl (https vs http)
• Update blueprint with final user selections before site creation (only updates existing properties)

Testing Instructions

Test 1: HTTPS URL in blueprint

1. Create a blueprint file with a defineSiteUrl step using https:

{
  "steps": [
    {
      "step": "defineSiteUrl",
      "siteUrl": "https://mysite.local"
    }
  ]
}

2. Open Studio and go to Add Site → Start from Blueprint → Choose Blueprint file
3. Upload the blueprint file
4. Verify:
   • Custom domain field shows mysite.local
   • Advanced settings are expanded
   • HTTPS toggle is ON
5. Create the site and verify it works with HTTPS

Test 2: HTTP URL in blueprint

1. Create a blueprint file with a defineSiteUrl step using http:

{
  "steps": [
    {
      "step": "defineSiteUrl",
      "siteUrl": "http://mysite.local"
    }
  ]
}

2. Upload the blueprint file
3. Verify:
   • Custom domain field shows mysite.local
   • HTTPS toggle is OFF

Test 3: URL with port (port is stripped)

1. Create a blueprint file with a port in the URL:

{
  "steps": [
    {
      "step": "defineSiteUrl",
      "siteUrl": "https://mysite.local:8443"
    }
  ]
}

2. Upload the blueprint file
3. Verify custom domain field shows mysite.local (port is stripped - domain validation doesn't support ports)

Pre-merge Checklist

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

[wpmobilebot]

📊 Performance Test Results

Comparing 815dff1 vs trunk

site-editor

Metric	trunk	815dff1	Diff	Change
load	2843.00 ms	2850.00 ms	+7.00 ms	🔴 0.2%

site-startup

Metric	trunk	815dff1	Diff	Change
siteCreation	7068.00 ms	7094.00 ms	+26.00 ms	🔴 0.4%
siteStartup	3923.00 ms	3922.00 ms	-1.00 ms	🟢 -0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change

[sejas]

I tested the PR with and without https and I confirm Studio pre-fills the custom domain extracting it from defineSiteUrl step.

The only case that fails is Test 3: URL with port - Verify custom domain field shows mysite.local:8443 (port preserved). I don't see the port preserved, and I'm not sure if we should support it at all.

[sejas]

Verify custom domain field shows mysite.local:8443 (port preserved)

If we want to preserve the port we might need to use host instead of hostname. Although I'm not sure if we should just show a warning or error to avoid falling into a rabbit hole.

Suggested change

	values.customDomain = url.hostname;
	values.customDomain = url.host;

[bcotrim]

Good catch! This is intentional - we're using url.hostname instead of url.host to strip ports.

The reason is that domain validation (getDomainNameValidationError in common/lib/domains.ts) doesn't support ports:

1. The regex pattern doesn't allow : characters
2. Validation requires the domain to end with .local

If we preserved the port (e.g., mysite.local:8443), users would see a validation error in the form. Stripping the port avoids this issue.

I've updated the PR description to reflect this behavior. 👍

[sejas]

It works as expected. The advance settings are expanded when suing the site url step definition, and the custom domain is pre-populated as expected. I also modified the pre-populated domain and I confirm it respected my custom domain.