v0.21.4

Fixed

• A deployment no longer fails between a platform upgrade and the next
  sync. The sync report records the version of the Markdown its lengths
  were measured on, documentLengths.markdownVersion, and the gate compares
  the content health page's length notes with what the MCP server returns
  only when that version is the one the build writes. After 0.21.0 changed
  the Markdown, every deployment before the first sync failed on notes the
  last sync had measured on the old text.

PUBLISHED_MARKDOWN_VERSION in @ctcstack/ctcdocs-core/published-markdown
moves whenever the Markdown version of a page changes.