Rewrite the add-on changelog for people upgrading

[dougrathbone]

Summary

The add-on changelog is what Home Assistant shows on upgrade. It now leads with upgrade steps, links issues and releases back to this repository, and leaves internal release mechanics out. Older notes are archived rather than deleted.

Changes

• Keep 1.22.0 onward in the add-on changelog. Move earlier releases to homeassistant-addon/CHANGELOG-archive.md, and fix the 1.0.0 date.
• Add Breaking changes and Action required sections, including the PIN-in-debug-logs step, force-arm becoming its own option, and the pending-vs-disarmed alarm change.
• Say when a repeated fix is a different cause. The 1.35.1 Toolkit catalogue fix is called out as separate from the 1.34.14 server-mode fix.
• Mark versions that never reached the add-on repository (including 1.28.0, 1.34.0, 1.34.2, and 1.34.5) and name the later version that included the changes.
• Replace bare issue numbers with full links, link each published version heading to its GitHub release, and drop internal-only bullets. A release with nothing user-facing is one maintenance line.
• Check the file in CI: real dates, section order, no placeholders, no backticks, no empty sections, and no bullet past 40 words. New version headings inserted by the release tool include the release link.

Test plan

• npm test passes locally with no failures
• New code has unit test coverage (aim for ≥ 60% on changed files)
• Existing tests were not broken or removed without justification

Checklist

• Version bumped in package.json and homeassistant-addon/config.yaml (if releasing)
• CHANGELOG.md updated (if releasing)
• No sensitive data or credentials included

Not a version bump. The notes describe releases that already shipped, including 1.36.0 and 1.35.3 from master.