feat: add control and custom quota grafana dashboards

[yindia]

Adds two built-in operational Grafana dashboards to the Helm chart, covering resource health and custom quota consumption. They drop into charts/capsule/dashboards and are rendered by the existing dashboards ConfigMap template, gated behind monitoring.dashboards.enabled. No controller, template, or dependency changes are needed.

Dashboard	UID	What it shows	Key metrics
Capsule / Control	capsule-control	Ready and health conditions across every Capsule resource, with a clear view of what is currently not working	capsule_*_condition (generic {__name__=~"capsule_.+_condition"}), capsule_tenant_namespace_count
Capsule / Custom Quota	capsule-customquota	Usage, limit, available and per item consumption for both namespaced and cluster scoped custom quotas	capsule_custom_quota_resource_*, capsule_global_custom_quota_resource_*

The Control dashboard queries conditions by metric name pattern, so it automatically covers every condition family that exists now or is added later, without per kind maintenance.

Everything was validated end to end against a live controller in a kind cluster with kube-prometheus-stack: resources applied from example/, metrics scraped through a ServiceMonitor into Prometheus, and both dashboards loaded into Grafana and confirmed to populate with real data.

Fixes #1925

[yindia]

cc: @oliverbaehler @Svarrogh1337