Devex: Add workflow to assign PR reviewers

[tristanlabelle]

This workflow will replace CODEOWNERS and address two issues:

1. CODEOWNERS can only match one rule, so it can't add two sets of reviewers for changes straddling frontend and backend.
2. It's easy to forget to add reviewing teams, which hinders cross-participation in code reviews.

New GitHub workflows are untestable, so this is scoped to github.event.pull_request.user.login == 'tristanlabelle'. I will test it after merging, then follow up with a PR that switches us from CODEOWNERS.

Testing

Will test after merging (currently only targeting PRs of yours truly).

For maintainers

• Maintainers can push commits to my branch
• Maintainers can merge this PR for me

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Project	Deployment	Actions	Updated (UTC)
couchers	Ready	Preview	May 15, 2026 10:16am

[aapeliv]

this is okay with me, but can we write the rules in an easy file, and have the actions script read it? that way you don't need to figure out what the script does to update codeowners

[tristanlabelle]

@aapeliv The easy way would be to name rules based on the team being assigned, but we'll need a new team for docs changes. Otherwise, I'd have to invent a (yml?) format, since the filters are more complex than CODEOWNERS supports, and delegate to a Python script to parse it. Let me know your preference.

[tristanlabelle]

And for the first option, I believe the dorny/path-filters can read its filters from a file so that'd get us pretty close to your request.

[aapeliv]

Yeah I think you could just come up with a simple syntax, it doesn't need to be complicated. And you can either wrangle the actions script into the required form, or write a python script or similar?

If you feel it's too difficult and you're not up for it, maybe we can merge as is too? I just think this is quite hard to modify in the future?

[aapeliv]

Also we can make a team for translation/docs if you wish

[tristanlabelle]

@aapeliv I found a pretty clean solution, and scoped the workflow to my PRs so I can test it post merge before switching from CODEOWNERS.

[tristanlabelle]

@aapeliv (Ready for review)

[aapeliv]

looks great, thank you!

[github-actions]

📝 Release Notes

This PR does not need to be included in release notes.

Reason: This PR adds an internal GitHub workflow for automatically assigning code reviewers, which is a developer experience and repository maintenance improvement. It does not affect the product for end users or represent major user-facing technical infrastructure.

🤖 Bot Debug Information

Model: couchers.openai.gpt-5.4
Decision: exclude
Reasoning: This PR adds an internal GitHub workflow for automatically assigning code reviewers, which is a developer experience and repository maintenance improvement. It does not affect the product for end users or represent major user-facing technical infrastructure.