Link references in review comments; prepare org bodies !146

• Review thread comments render through FormattedBodyView (Markdown, as the web renders them; the forge sends no body_format for them), so #N, !N and owner/name#N link in-app relative to the MR's repo. DiffView gets .referenceNavigation() for the threads it shows.
• linkReferences(in:repo:) moves from MarkdownView to BodyReferences.swift; new BodyReferenceOrgTests run it over OrgSwift's attributed output (verbatim, code and existing links skipped).

Org bodies: OrgView has no hook, so krz/org-swift!9 adds textTransform. The wiring is on branch org-body-refs (one commit on top of this one), which bumps the org-swift requirement to 0.7.0 and needs that tag before it builds.

574 unit tests, 0 failures; Release build compiles.