First PR in the staged plan from
[#33370](https://github.com/fleetdm/fleet/issues/33370#issuecomment-4394807680).
Adds unit tests for several testable helpers in `cmd/fleet/serve.go` —
argument stringification, TLS profile config, license initialization,
and the missing-migrations warning.
The migrations-warning test required threading `io.Writer` through
`printMissingMigrationsWarning` so it can pass `*bytes.Buffer` instead
of mutating `os.Stdout`. The other two database-state print functions
stay as-is since they aren't tested in this PR.
**Related issue:** Part of #33370 (intentionally not using auto-close
keywords since this is the first of multiple PRs against this issue).
# Checklist for submitter
If some of the following don't apply, delete the relevant line.
## Testing
- [x] Added/updated automated tests
## Database migrations
_N/A — no database migrations in this PR._
## New Fleet configuration settings
_N/A — no new configuration settings._
## fleetd/orbit/Fleet Desktop
_N/A — no agent code changes._
Rajendra kadam
ace3804086