[sarankumar1325]

Fixes the "unstability" typo (-> "instability") and the missing "is" in the extensions value comment in values.yaml ("This function is in tech preview stage, do expect instability ..."). The comment is a ## line, so README.md is unchanged after running helm-docs v1.9.1. A patch change fragment is included. helm template output is identical before and after, helm lint passes, and ./scripts/lint-changelog.sh passes.

Checklist:

• I have added a change fragment with the right bump according to versioning
• I have updated the documentation according to documentation
• The change fragment describes all the changes in this pull request according to changelog.
• I wrote this PR with the help of a LLM but I fully vetted the work before raising this PR for review
• Any new values are backwards compatible and/or have sensible default.
• I have signed off all my commits as required by DCO.
• I have created a separate pull request for each chart according to pull requests
• My build is green (troubleshooting builds).