docs(changelog): release v0.28.0

Rolls [Unreleased] into [0.28.0] - 2026-10-23 and leaves a fresh empty
[Unreleased] on top. Merges the repeated Fixed / Security / Added
headings separate PRs had added into one of each, in canonical order,
adds the mandatory headline (change one thing without restating the
rest) and grouped entries for the user-facing changes since v0.27.0
that had none: alter navigation / alter menu, ALTER PAGE addresses for
table cells, object-list items and slots, export level and Protected
modules, configuration JVM options in run --local, and the check,
describe, pages, layout and integration fixes. Adds a v0.28.0 release
post to the docs-site blog.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014DfG9NpcA979LzU5R8j1Ay

Author: ako