Add MaintainedApp identifier to not found error

[thomastysong]

Changes

When a Fleet-maintained app is not found, the error message now includes the app identifier (ID or slug) to help with debugging.

Before: MaintainedApp was not found
After: MaintainedApp 123 was not found or MaintainedApp zoom/darwin was not found

Related issue

Fixes #37896

Checklist

• Changes file added (see changes/37896-maintainedapp-notfound-error)
• Code follows existing patterns (notFound().WithID() and notFound().WithName())
• Tests added for not-found error cases

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 65.96%. Comparing base (df36372) to head (35075c1).
⚠️ Report is 12 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #37908      +/-   ##
==========================================
+ Coverage   65.94%   65.96%   +0.02%     
==========================================
  Files        2367     2368       +1     
  Lines      188262   188630     +368     
  Branches     8101     8101              
==========================================
+ Hits       124146   124429     +283     
- Misses      52773    52833      +60     
- Partials    11343    11368      +25     

Flag	Coverage Δ
backend	67.70% <100.00%> (+0.02%)	⬆️

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[noahtalerman]

Thanks @thomastysong! Setting this PR to draft while we bring a user story (to be created) through drafting: https://fleetdm.com/handbook/engineering#review-a-community-pull-request

[allenhouchins]

@noahtalerman FYI. I ran into this in dogfood today (pre and post 4.79.0 RC): https://fleetdm.slack.com/archives/C071NNMSP2R/p1767723031616899

I still think we should take a look at this fix but seeing this across multiple environments leads me to believe something else might be going on that lead to this error message popping up in the first place.

[allenhouchins]

@thomastysong I was hoping you could confirm something for me. Are you using the Docker Desktop for macOS Fleet-maintained app? If so, just yesterday we had to update the slug to address an issue. The FMA was previously quitting the docker binary instead of the Docker Desktop app, leaving Docker Desktop in a broken state. If you update your slug from docker/darwin to docker-desktop/darwin, does the error go away?

I still agree we need to have clearer messaging in the error log so thanks for submitting!

[thomastysong]

@allenhouchins Yes! Thanks for the reply. We did update the slug and the error went away. It took a bit of investigation to understand which app was affected, hence the concern raised in the issue/pr. But yes we are no longer seeing the error after updating.

@thomastysong I was hoping you could confirm something for me. Are you using the Docker Desktop for macOS Fleet-maintained app? If so, just yesterday we had to update the slug to address an issue. The FMA was previously quitting the docker binary instead of the Docker Desktop app, leaving Docker Desktop in a broken state. If you update your slug from docker/darwin to docker-desktop/darwin, does the error go away?

I still agree we need to have clearer messaging in the error log so thanks for submitting!

[allenhouchins]

@thomastysong Thank you!

[MagnusHJensen]

@noahtalerman Did you forget to mark it draft?

[noahtalerman]

Did you forget to mark it draft?

Yes!