[codex] Harden KEDA chart behavior and reviewer handoff docs

[RayLi-Muye]

Summary

Hardens the render-worker chart after the multi-agent review loop and improves the GitHub-facing reviewer handoff.

Closes #13.
Closes #14.

Acceptance Criteria

• KEDA-enabled deployments omit spec.replicas so Helm does not reset worker replica count during upgrades.
• AWS GPU/SQS example renders KEDA TriggerAuthentication and ScaledObject authenticationRef.
• ConfigMap and Secret values render as strings even when provided as numeric values.
• README and evidence map explain what reviewers should evaluate.
• Roadmap, issue templates, PR template, and delivery prompts support continuation across delivery nodes.

Validation

• /tmp/renderfarm-helm/darwin-arm64/helm lint charts/render-worker
• /tmp/renderfarm-helm/darwin-arm64/helm template render-worker charts/render-worker
• /tmp/renderfarm-helm/darwin-arm64/helm template render-worker charts/render-worker -f examples/values-local.yaml
• /tmp/renderfarm-helm/darwin-arm64/helm template render-worker charts/render-worker -f examples/values-aws-gpu-sqs.yaml
• Ruby YAML assertion: replicas omitted under KEDA
• Ruby YAML assertion: KEDA TriggerAuthentication/authenticationRef rendered
• Ruby YAML assertion: ConfigMap/Secret numeric values render as strings
• Ruby YAML parse check for GitHub issue templates and workflow

Evidence Update

• README, docs, roadmap, and evidence map updated
• docs/delivery-prompts.md added for future delivery nodes

Continuation Prompt

A future contributor or agent should be able to continue with:

Implement #15 by adding Kubernetes schema validation and Helm install integrity checks to GitHub Actions. Validate default, local, and AWS GPU/SQS rendered manifests. Update docs/evidence-map.md with CI hardening evidence and keep the workflow pinned and readable.

Security Notes

No customer assets, renderer binaries, license files, credentials, or cloud account secrets are included. KEDA authentication is modeled through pod identity placeholders only.