Retire runtime/API/UI monitored-system volume enforcement now that infrastructure monitoring is no longer capped.
Keep only legacy metadata scrubbing and purchase-start compatibility for old max_monitored_systems references.
Rename the remaining preview surface to monitored-system impact and make previews explanatory rather than save-blocking.
Update subsystem contracts and RA7 evidence for the caps-retired invariant.
Simplify server config by consolidating BackendHost and BackendPort into
a single BindAddress field. The port is now solely controlled by FrontendPort.
Changes:
- Replace BackendHost/BackendPort with BindAddress in Config struct
- Add deprecation warning for BACKEND_HOST env var (use BIND_ADDRESS)
- Update connection timeout default from 45s to 60s
- Remove backendPort from SystemSettings and frontend types
- Update server.go to use cfg.BindAddress
- Update all tests to use new config field names