Restore the replaced pipeline's synthetic fence newline so a real trailing
blank line inside a fence survives CodeBlock's display trim, and pin it
plus header-only tables in the DOM-parity corpus. Route
extractMarkdownPlainText through parseGfm so the grammar has one source.
Document the fixture provenance check (all 46 fixtures reproduce
byte-identically from react-markdown at 9e8101b800), the deliberate
O(prefix) divergence memcmp, the per-arm scope of grammar consistency,
the React 18 MathML namespace limitation, and the prefix-equivalence
corpus constraint.
Port the two master-side markdown fixes onto the mdast renderer:
cjkFriendlyStrong joins both parse.ts grammars as a micromark extension
(ex remark plugin), and inline-code HTTP(S) URLs gain the safe anchor in
render.tsx without normalizeUri. Re-record the two new web-e2e goldens
whose footer clock spacing diverged from the nine established goldens,
and drop the timing-flaky LLM duration segment one of them captured.
