Round-1 review found two issues:
- [regressions] Inserting a transcript line VERBATIM as a paragraph is unsafe on the
git-sync doc->markdown->doc round-trip: the paragraph serializer emits text with no
block-escape, so a line starting at col 0 with `- `/`> `/`# `/`1. `/```` ``` ````/`|`/
`> [!info]` silently re-parses into a list/quote/heading/code/table/callout (the last
hits the #359 callout machinery). Safe under the host contract (every line prefixed
`You:`/`Speaker N:`, which starts with a letter) but the helper didn't enforce it, and
leading-whitespace / stray lines exist. Fix: trim each kept line (drops the indent leak),
and if it STILL begins with a col-0 markdown block trigger, prepend an invisible
zero-width space (U+200B) so the trigger isn't at col 0 — the round-trip keeps it a
paragraph. (Backslash-escape was rejected: `marked` consumes the `\` on re-import, so it
would render visibly then vanish. ZWSP is invisible and never markdown-escaped.) The
serializer's missing block-escape is the pre-existing root cause; this is the boundary
defense. Prefixed transcript lines never match the trigger regex → left byte-exact.
- [test-coverage] The "inserted as TEXT, not HTML/markdown" contract wasn't locked (all
test strings were plain alphabet). Added a test that inserts `<b>bold</b>
<script>alert(1)</script> and *stars* and [link](x)` (with Bold/Italic/Link marks
registered so an insertContent(html) regression would parse them) and asserts one
verbatim text node, no marks, and getHTML() has no live tags.
Verified: apps/client tsc --noEmit 0 errors; gitmost bridge tests 4 passed; a NEW
prosemirror-markdown round-trip test (real convertProseMirrorToMarkdown ->
markdownToProseMirror) proves bare triggers corrupt while the ZWSP-neutralized form stays
a single byte-preserved paragraph and normal You:/Speaker N: lines round-trip byte-exact —
3 passed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
