The standard Prometheus ProcessCollector uses procfs (Linux-only /proc),
so process_resident_memory_bytes and process_virtual_memory_bytes were
silently absent on FreeBSD, Darwin, and other non-Linux platforms.
- Switch to a custom prometheus.Registry to isolate GOST metrics from
the default registry auto-registrations
- Add gopsutil/v3-based process collector (process_other.go) for
platforms without procfs (!linux && !windows)
- Keep standard ProcessCollector (process_standard.go) on Linux/Windows
- Update metrics service and handler/metrics to serve from
promhttp.HandlerFor(customRegistry) instead of promhttp.Handler()
- Add Registry() accessor for the custom registry
Fixesgo-gost/gost#509
ginuerzh