Added new endpoints:
- GET /v1/system/info
- GET /v1/runtime/gates
- GET /v1/limits/effective
- GET /v1/security/posture
Added API runtime state without impacting the hot path:
- config_reload_count
- last_config_reload_epoch_secs
- admission_open
- process_started_at_epoch_secs
Added background watcher tasks in api::serve:
- configuration reload tracking
- admission gate state tracking
Alexey