bug(kagent): Default Kagent bundled agents crash loop due to missing secrets

Problem

When installing Kagent without the --set agents.*.enabled=false flags documented in kagent-feast-mcp/README.md (lines 138-149), the default bundled agents (argo-rollouts-conversion-agent, cilium-debug-agent, k8s-agent, etc.) crash loop with CreateContainerConfigError because they expect a kagent-openai secret that doesn't exist in this project's setup.

These agents collectively consume ~2.3GB of RAM before crashing, which on constrained environments (e.g., 8GB WSL2 hosts) prevents the actual kubeflow-docs-agent pod from being scheduled.

Current Mitigation

The README Step 6 already includes the correct --set flags to disable these agents. However:

1. If a contributor installs kagent from the upstream kagent docs (without these flags), they hit this crash with no explanation.
2. There's no troubleshooting entry for CreateContainerConfigError or kagent-openai secret in the README.

Proposed Fix

Add a Troubleshooting entry to kagent-feast-mcp/README.md under the existing Troubleshooting section:

### Default agents crash with CreateContainerConfigError

If you installed kagent without the `--set agents.*.enabled=false` flags from Step 6,
the bundled agents will crash because they require a `kagent-openai` secret.
Either reinstall with the flags above, or delete the extra agents:

kubectl delete agent argo-rollouts-conversion-agent cilium-debug-agent \
  cilium-manager-agent cilium-policy-agent helm-agent istio-agent \
  k8s-agent kgateway-agent observability-agent promql-agent -n <YOUR_NAMESPACE>

File

• kagent-feast-mcp/README.md — Troubleshooting section

Context

Discovered during local Kagent PoC validation — #59 (comment)

Note: @SanthoshToorpu noted that kagent install should remove these.

Confirmed that the --set flags do work — this issue is about documenting the fallback for when those flags are missed.

Edit kagent-feast-mcp/README.md in the existing Troubleshooting section. First compare the proposed entry with the Step 6 installation flags and confirm the listed agents and namespace placeholder; done means the README explains the CreateContainerConfigError and kagent-openai secret problem and documents both recovery options.