Console plugin: Dashboard overview cards for build health

[vtz]

Context

Add summary cards to the OpenShift Developer perspective dashboard (or a dedicated Bob dashboard page) giving an at-a-glance view of build system health.

Depends on: #44 (scaffold), #45 (list page)

Scope

• Active Builds card: count of Running BuildJobs with links
• Build Success Rate card: succeeded vs failed over last N runs
• Recent Failures card: list of recently failed builds with quick links to logs
• Toolchain Status card: count of Ready vs Building vs Failed toolchains
• Optional: integrate with the Developer perspective dashboard via console.dashboards/overview/ extension points, or create a standalone "Bob Overview" page

Extension Points

{
  "type": "console.dashboards/overview/health/resource",
  "properties": {
    "title": "Build Jobs",
    "resources": [{ "group": "bob.redhat.com", "version": "v1alpha1", "resource": "buildjobs" }]
  }
}

Notes

• Cards should respect namespace scope for developer users
• Admin view can show cluster-wide aggregation