Add Harness CD pipeline for netcore-sample-app

[Komali612]

Automated Harness CD config for netcore-sample-app, generated by NetcoreCDAgent (cookbook).

What this adds (Harness Git Experience)

• Shared stage template deploy_dotnetcore_k8s_bluegreen (v1.0) — blue-green on Kubernetes. Authored once; referenced, never forked.
• service.yaml — artifact = the CI image (nexus.example.com/netcore-sample-app), tag supplied at runtime by the trigger.
• environments/ + input-sets/ — per-env values (dev, staging, prod); approval-gated: staging, prod.
• pipeline.yaml — thin stage that references the shared template.
• triggers/on-new-artifact.yaml — deploys the new image tag automatically.
• manifests/ — plain K8s (the image lives only in values.yaml).

Deploy strategy

Blue/Green: stage the new version behind the -stage service → health check → approval (prod) → swap primary↔stage. Rollback = swap back.

Review and merge when ready — this PR is not auto-merged.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud