By default /api/v1/monitoring/stats and /api/v1/health-checks/status are
public (current behavior, dashboard needs them pre-login). Users deploying
DashCaddy on the open internet can now set:
MONITORING_PUBLIC=false
...or add 'monitoring: { public: false }' to config.json to require auth.
This prevents anonymous disclosure of CPU/memory/disk data.
The check uses env var first, then config.json, then defaults to true
(preserves current behavior for existing users).