Bring KiteControllers' changelog to the release convention

[1-Bort-1]

Bring KiteControllers' changelog to the release convention

Bring CHANGELOG.md to the one convention the box releases from, so agent release / "release " on Slack opens the bump PR without a refusal (1-Bart-1/Agents#608). Pending notes sit under one ## Unreleased header above every release (or as files in changelog.d/), grouped under ### Added / ### Fixed / ### Changed. Every released section is headed ## <PackageName> vX.Y.Z YYYY-MM-DD: ## level, v before the version, ISO date, no dash, no brackets, no "(unreleased)". Rewrite headers only; leave the note text as it is. Check: bin/release --dry-run (the box copy, rules/release in 1-Bart-1/Agents) on the PR head reads the version and the notes.

In this repo: releases use vX.Y.Z - YYYY-MM-DD (drop the dash); there is no ## Unreleased yet, add an empty one.

[1-Bort-1]

Rewriting CHANGELOG.md release headers from ## KiteControllers vX.Y.Z - YYYY-MM-DD to ## KiteControllers vX.Y.Z YYYY-MM-DD and adding an empty ## Unreleased on top; note text untouched. Builds on main, no open PR touches CHANGELOG.md. Leaving out bin/install: it refuses the box's Julia 1.13 under -y (and runs the test suite, edits ~/.bashrc), which this markdown-only change does not need — queued as its own cleanup task.