Store links from Markdown import and connected-app writes on the hyperlink mark #335

Parent

#328. Related: #174

Problem

Markdown import and connected-app writes store links on the old link mark. The pad cannot preview or edit such a link. parseMarkdown uses the export manager (markdownExport.ts). StarterKit's link comes first there, so it claims the Markdown link token.

What to do

In markdownExtensions (markdownExport.ts), move Hyperlink before ...migrationExtensions. @tiptap/markdown picks the first extension that claims a token. The claim order is not documented, so add a comment on the order. Export still serializes stored link marks, so keep link in the set. Do not build a second manager.

Checked with Bun on 2026-09-29: the reorder gives hyperlink, and export output is byte-identical. The reorder sets no title attr. On hyperlink, title is cached preview metadata.

Acceptance

• parseMarkdown('[Budget](https://example.test/p?id=a)') gives a hyperlink mark with the same href.
• **[bold](https://a.test)** keeps bold and gets hyperlink.
• Export of stored link marks is unchanged.
• A bare URL alone on its line still becomes media.
• A unit test in markdownImport.test.ts pins the mark name. Prove it by sabotage: undo the reorder, and the test must fail.
• In the pad, an imported link opens the hyperlink preview, and Edit works.
• The <a href> bullet in apps/hocuspocus.server/CLAUDE.md §HTTP Modules no longer calls this a known divergence. CHANGELOG.md [Unreleased] has a ### Fixed line.

Out of scope

Rewriting stored link marks. #174. #244.