Add 6 new Prometheus metrics for richer observability:
- auth_attempts_by_country_total (counter by country)
- commands_executed_total (counter by shell via OnCommand callback)
- human_score (histogram of final detection scores)
- storage_login_attempts_total, storage_unique_ips, storage_sessions_total
(gauges via custom collector querying GetDashboardStats on each scrape)
Add optional bearer token authentication for the /metrics endpoint via
web.metrics_token config option. Uses crypto/subtle.ConstantTimeCompare.
Empty token (default) means no auth for backwards compatibility.
Also adds "cisco" to pre-initialized session/command metric labels.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add internal/metrics package with dedicated Prometheus registry exposing
SSH connection, auth attempt, session, and build info metrics. Wire into
SSH server (4 instrumentation points) and web server (/metrics endpoint).
Add dockerImage output to flake.nix via dockerTools.buildLayeredImage.
Bump version to 0.7.0.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
