Closes AC-2318. Enable static check directly (since golangci-lint's version is still broken) and fix issues. Partially because it's a good idea, partially because Fairyproof asked.

## Review Checklist

**If any item is not complete, the merge request is not ready to be reviewed and must be marked `Draft:`.**

- [x] The merge request title is in the format `<change type>(<change scope>): <short description> [<task id>]`
  - For example, `feat(cli): add QR code generation [AC-123]`
  - For details, see [CONTRIBUTING.md](/CONTRIBUTING.md)
- [x] The description includes `Closes <jira task ID>` (or rarely `Updates <jira task ID>`)
- [x] The change is fully validated by tests that are run during CI
  - In most cases this means a test in "validate.sh"
  - In some cases, a Go test may be acceptable
  - Validation is not applicable to things like documentation updates
  - Purely UI/UX changes can be manually validated, such as changes to human-readable output...