Move the Unreleased entries into 0.2.41, dated 2026-09-24, add the
full-diff link, and set KPlugin.Version to the released version.

Documentation impact: CHANGELOG.md moves already-reviewed Unreleased
entries (verified against the v0.2.40..HEAD scope) into the versioned
section. No guide or TODO changes: the release ships the behavior those
guides already describe; upstream latest remains 0.65.0, already
reviewed.