BRE2-1034: Add support for secrets

[drewmalin]

  brev secrets ls
  brev secrets create --name my-secret --value supersecret
  brev secrets get --id <ID>
  brev secrets get --name my-secret
  brev secrets set-value --id <ID> --value rotated-secret
  brev secrets get-value --id <ID>
  brev secrets get-value --id <ID> --version 2
  brev secrets delete --id <ID>

Recording:

Screen.Recording.2026-09-03.at.14.11.06.mov

[patelspratik]

might be worth mentioning that this will not affect any launchable usages, as those are tied to a specific version? Or some other note about the consequences of the new version.

[patelspratik]

I wonder if we'll want to be able to get usages at some point.