Core: Fix composition of storybooks on same origin

[ndelangen]

Closes #25957

What I did

This makes it possible to have refs share the same origin as each other and as well as the main storybook.

This is useful if you have static-storybooks in static directories

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

What I did was:

• I created a sandbox
• I ran yarn build-storybook in the sandbox
• I renamed the static-storybook directory to foo and copied it into the static directory of the sandbox
• I added a ref to the sandboxs main.ts file:

  refs: {
    'test-component': {
      title: 'test-component',
      url: 'http://localhost:6006/foo/',
    },
  },

• I ran yarn storybook (dev-mode).
• I was able to observe the preview load correctly
• I was able to switch between the ref and the main
• I able to verify the currect iframe was being shown on both routes

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli/src/sandbox-templates.ts

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This pull request has been released as version 0.0.0-pr-26304-sha-8cbb06d9. Try it out in a new sandbox by running npx storybook@0.0.0-pr-26304-sha-8cbb06d9 sandbox or in an existing project with npx storybook@0.0.0-pr-26304-sha-8cbb06d9 upgrade.

More information

Published version	0.0.0-pr-26304-sha-8cbb06d9
Triggered by	@ndelangen
Repository	storybookjs/storybook
Branch	norbert/composition-loading-state-fix
Commit	8cbb06d9
Datetime	Tue Mar 5 14:54:44 UTC 2024 (1709650484)
Workflow run	8158297657

To request a new release of this pull request, mention the @storybookjs/core team.

core team members can create a new canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=26304

[shilman]

Great job!! 💪