Log forwarded 4xx errors

[Askir]

Relies on: https://github.com/timescale/savannah-public/pull/49
The errors for these cases are still suboptimal:

• Creating more than 2 free services (insufficient permission -> Error: Unauthorized. Entitlement check has failed.)
• Forking more than 2 free services (insufficient permission -> Error: Unauthorized. Entitlement check has failed.)
• Forking before a backup is read (still gives a 500)
• Forking to an invalid (too early timestamp) (still gives a 500)

Will dive a bit deeper into graphql to try get better errors. At least it should be propagated with this.

[nathanjcochran]

Left a couple minor comments, but no show-stoppers. Looks good to me ✅

I definitely think there's more we could do to clean up the error handling, but that could be done in a follow-up. This gets the job done for now 👍.

[cevian]

Looked over this and looks reasonable but will let @nathanjcochran take lead on review. Suggest to add text to CLAUDE.md to specify how this should be handled