Replace inline Path.home() / '.hermes' / 'profiles' detection in both CLI
and gateway /profile handlers with the existing get_active_profile_name()
from hermes_cli.profiles — which already handles custom-root deployments,
standard profiles, and Docker layouts.
Fixes /profile incorrectly reporting 'default' when HERMES_HOME points to
a custom-root profile path like /opt/data/profiles/coder.
Based on PR #10484 by Xowiek.