add command for creating k3d debug cluster identical to one used in E2E

[gflarity]

What type of PR is this?

Developer Tools

What this PR does / why we need it:

This PR adds a new setup-debug-cluster CLI command that creates a K3D cluster identical to the one used in E2E tests. This enables developers to easily reproduce E2E test environments locally for debugging purposes.

The command handles all setup steps including:

• Creating the K3D cluster with the same configuration as E2E tests
• Setting up a Docker registry
• Pre-pulling and caching test images
• Deploying Grove operator via Skaffold
• Installing Kai scheduler via Helm

Key changes:

• New operator/e2e/cmd/setup-debug-cluster/main.go CLI tool using Kong for argument parsing
• Refactored DefaultClusterConfig() in k8s_clusters.go to be the single source of truth for cluster configuration (including node labels and taints)
• Added DeleteCluster() and GetKubeconfig() helper functions for reuse
• Updated shared_cluster.go to use DefaultClusterConfig() with overrides instead of duplicating configuration
• Improved registry cleanup to check for port conflicts with other containers

Which issue(s) this PR fixes:

NONE

Special notes for your reviewer:

The CLI supports all the same configuration options as the E2E cluster setup, with sensible defaults. When run interactively, it waits for Ctrl+C and then tears down the cluster. When run non-interactively, it leaves the cluster running for manual teardown.

Example usage:

cd operator/e2e/cmd/setup-debug-cluster
go run . -v

Does this PR introduce a API change?

NONE

Additional documentation e.g., enhancement proposals, usage docs, etc.:

NONE