Description

While reviewing recent PRs related to ChaosEngine manifest generation, I noticed a structural flaw in how KubernetesYamlService.ts handles tolerations arrays for both runners and experiments.

Currently, when the UI updates the manifest, it has a tendency to overwrite existing tolerations rather than appending to them. If a user has pre-configured multiple node tolerations (e.g., for different edge/cloud node pools) and then updates the experiment via the UI, the serialization logic drops the existing array elements.

Proposed Solution

1. Update KubernetesYamlService.ts to explicitly merge incoming tolerations with ...(manifest.spec.components?.runner?.tolerations || []).
2. Ensure the same defensive spreading is applied to manifest.spec.experiments[0].spec.components.tolerations.
3. Add defensive unit tests specifically for the serialization merge behavior to prevent future PRs from inadvertently introducing array overwrites.

I can submit a PR for this immediately to lock down the data integrity.