Allow preserving file paths when including assets from config key entry

[vividviolet]

WHY are these changes introduced?

When multiple configKey entries reference different source directories or files that produce the same output-relative path, the last writer silently wins. This makes it impossible to detect accidental file collisions when directory structures need to be preserved in the output.

WHAT is this pull request doing?

Adds a preserveFilePaths option (default false) to configKey inclusion entries. When enabled:

• Files are written to the output directory preserving their relative paths from the source directory, rather than being flattened to unique basenames.
• A collision check is enforced across all entries in the same build: if two different sources would produce the same output-relative file path, an error is thrown immediately with a descriptive message indicating which file caused the conflict.
• A shared usedFiles set is threaded through all configKey entries so cross-entry collisions are detected, not just within-entry ones.
• The existing usedBasenames deduplication logic is preserved for entries where preserveFilePaths is false.

The collision check is extracted into a single assertNoCollision helper used by both the directory and single-file copy branches.

How to test your changes?

Unit tests should be sufficient

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've considered analytics changes to measure impact
• The change is user-facing — I've identified the correct bump type (patch for bug fixes · minor for new features · major for breaking changes) and added a changeset with pnpm changeset add

[vividviolet]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Allow preserving file paths when including assets from config key entry #7389 👈 (View in Graphite)
• Fix Dev Server to allow serving static assets from a shared folder outside of the extension directory #7386
• address png encoding bug, path changes #7378
• Add assets config key support for UI extension points #7363
• support bundle folder in the bundle ui step config #7340
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[melissaluu]

/snapit

[github-actions]

🫰✨ Thanks @melissaluu! Your snapshot has been published to npm.

Test the snapshot by installing your package globally:

pnpm i -g --@shopify:registry=https://registry.npmjs.org @shopify/cli@0.0.0-snapshot-20260424162325

Caution

After installing, validate the version by running shopify version in your terminal.
If the versions don't match, you might have multiple global instances installed.
Use which shopify to find out which one you are running and uninstall it.

[vividviolet]

/snapit

[github-actions]

🫰✨ Thanks @vividviolet! Your snapshot has been published to npm.

Test the snapshot by installing your package globally:

pnpm i -g --@shopify:registry=https://registry.npmjs.org @shopify/cli@0.0.0-snapshot-20260424215600

Caution

After installing, validate the version by running shopify version in your terminal.
If the versions don't match, you might have multiple global instances installed.
Use which shopify to find out which one you are running and uninstall it.