fix: enforce static node affinity for native Helm

[vigneshrajsb]

Summary

• Add the missing static node affinity expression for native Helm application-chart deployments.
• Keep the existing ON_DEMAND affinity and static toleration behavior.
• Add test coverage for static scheduling values.

Validation

• pnpm exec jest src/server/lib/nativeHelm/tests/helm.test.ts --runInBand
• pnpm run lint
• pnpm test
• pnpm run ts-check (fails on existing repo-wide TypeScript errors unrelated to this change)