Remove client secret from gRPC auth flow. The secret was originally included to support providers like Google Workspace that don't offer a proper PKCE flow, but this is no longer necessary with the embedded IdP. Deployments using such providers should migrate to the embedded IdP instead.
* **New Features**
* Access logs now include bytes_upload and bytes_download (API and schemas updated, fields required).
* Certificate issuance duration is now recorded as a metric.
* **Refactor**
* Metrics switched from Prometheus client to OpenTelemetry-backed meters; health endpoint now exposes OpenMetrics via OTLP exporter.
* **Tests**
* Metric tests updated to use OpenTelemetry Prometheus exporter and MeterProvider.
CLI: new expose command to publish a local port with flags for PIN, password, user groups, custom domain, name prefix and protocol (HTTP default).
Management/API: create/renew/stop expose sessions (streamed status), automatic naming/domain, TTL renewals, background expiration, new management RPCs and client methods.
UI/API: account settings now include peer_expose_enabled and peer_expose_groups; new activity codes for peer expose events.
