feat(helm): add resizePolicy and dnsConfig to pod spec

[younsl]

Summary

Adds two opt-in pod spec fields to the Helm chart:

• resizePolicy — container-level resize policy for in-place vertical scaling (Kubernetes 1.27+ with InPlacePodVerticalScaling feature gate). Lets operators avoid pod restarts on CPU/memory resize when desired.
• dnsConfig — pod-level DNS configuration, commonly used to tune ndots and cut down on unnecessary DNS lookups inside the cluster.

Both default to empty ([] / {}) and are rendered with with guards, so existing manifests are unchanged.

Changes

• helm/values.yaml: add resizePolicy and dnsConfig with documentation comments and example values for CPU / memory / ndots.
• helm/templates/deployment.yaml: render resizePolicy under the container spec (after resources) and dnsConfig under the pod spec (after tolerations).
• helm/README.md: regenerated via helm-docs.

Example

resizePolicy:
  - resourceName: cpu
    restartPolicy: NotRequired
  - resourceName: memory
    restartPolicy: RestartContainer

dnsConfig:
  options:
    - name: ndots
      value: "2"

Test plan

• helm lint helm/ passes
• helm template with default values: neither resizePolicy nor dnsConfig is rendered (no regression)
• helm template with the example above: resizePolicy placed at container scope, dnsConfig.options[].name=ndots at pod scope
• helm-docs regenerated; new rows added to helm/README.md

Note: chart version intentionally not bumped — leaving it to a separate release bump PR, consistent with project history.

[burningalchemist]

Hey @younsl, thank you for your contribution. I'll have a look today. 😃👍

[younsl]

Thanks @burningalchemist! Quick note: I skipped the chart version bump in this PR to follow the existing convention where feature/fix PRs land first and a separate Bump up helm chart to x.y.z PR handles the release — happy to adjust if you'd prefer it bundled.

[burningalchemist]

Hey @younsl, if you don't mind bumping up the version, that'd be great. Current workflow is a bit tricky but helps with testing anyway. Maybe I revisit it in the future.

For now, let's just bump up the version to 0.18.0 since there are new features. Could you also run make gen_docs from the helm directory afterwards? 🙂

[younsl]

Ready to merge

[burningalchemist]

@younsl released! Thanks again! 🙌

[younsl]

@burningalchemist This SQL Exporter has been running 24x7 in production at our payments company. Primarily used for visualizing DB connections and DB process lists. Thank you for maintaining such a great project.