docs(changelog): first-response jump scroll-settle fix (#6621)

[nesquena-hermes]

CHANGELOG stamp for #6621 (first-response jump no longer snaps back to bottom while streaming, shipped to the experimental channel). Code merged in 3a95d82; this is the separate release-PR CHANGELOG stamp per ship mechanics. Credit @pxxD1998.

[greptile-apps]

Greptile Summary

This release-process PR adds the experimental-channel CHANGELOG entry for the previously merged first-response jump scroll-settle fix.

• Documents that jumping to the first response no longer resumes bottom-following while that response streams.
• Describes the user actions that restore normal scroll following and credits the contributor.

Confidence Score: 5/5

The PR appears safe to merge because it only adds an accurate release-process changelog entry for behavior already merged.

The documented scroll-ownership behavior, release actions, placement, and attribution align with the implementation and established changelog conventions.

Important Files Changed

Filename	Overview
CHANGELOG.md	Adds an accurately placed and implementation-consistent entry under the Unreleased “Fixed” section.

_{Reviews (1): Last reviewed commit: "docs(changelog): first-response jump scr..." | Re-trigger Greptile}