fix: prevent crash in normalizeTable when body row has more cells than header - #4222

The serializeTable ragged-row coverage in tableNormalization.spec.ts
duplicated the existing serializeTable — row width mismatch suite in
stateToMarkdown.spec.ts (both #4222/#4190): same well-formed,
extra-cell-dropped, and short-row scenarios. Keeping two suites for one
behavior risks them drifting apart, so remove the redundant file and
keep the single existing suite as the source of truth.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

* test(muya): port MarkText regression cases (#4341/#4307/#4190)

Port three MarkText-specific regression cases from the legacy
`packages/muyajs` desktop specs into `@muyajs/core`'s own suite to lock
in behavioral fidelity for the migration off legacy muyajs. Tests only —
no engine changes.

- #4341 nested mixed lists (ul-in-ol / ol-in-ul): PASS. The state tree
  from MarkdownToState nests the differing-type list under the correct
  list-item (no paragraph collapse), and md -> state -> md round-trips
  identically. Ported as structural + round-trip assertions.
- #4190 table normalization (body row with more/fewer cells than the
  header): PASS. StateToMarkdown.serializeTable clamps each row to the
  header column count (extra cell dropped) and never throws. The legacy
  spec hand-built a malformed block tree for ExportMarkdown.normalizeTable;
  the muya equivalent hand-builds a malformed ITableState because a GFM
  round trip can never produce a ragged table.
- #4307 CJK strong flanking (`**"加粗"**` against a CJK boundary):
  documented engine GAP. marked@16 implements the CommonMark flanking
  rule literally and classifies CJK ideographs / Hangul as "other"
  (neither whitespace nor punctuation), so `**` adjacent to a CJK char
  with punctuation-bounded inner content does not open/close emphasis.
  Legacy muyajs shipped a custom tokenizer that treats CJK as punctuation
  for flanking; marked does not. The four CJK cases assert the CORRECT
  (legacy) behavior under `it.fails`, so the suite stays green while the
  gap exists and flips red the moment the gap closes. Sanity cases that
  already work are plain `it` so a future fix can't regress them.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

* test(muya): drop duplicate tableNormalization spec

The serializeTable ragged-row coverage in tableNormalization.spec.ts
duplicated the existing serializeTable — row width mismatch suite in
stateToMarkdown.spec.ts (both #4222/#4190): same well-formed,
extra-cell-dropped, and short-row scenarios. Keeping two suites for one
behavior risks them drifting apart, so remove the redundant file and
keep the single existing suite as the source of truth.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <[email protected]>

…n header (marktext#4222)

Fixes TypeError: Cannot read properties of undefined (reading 'width')
(issue marktext#4190). When a table body row contains more cells than the header,
columnWidth[j] is undefined for extra columns. Guard the width-calculation
loop with Math.min and slice body rows to header column count before
rendering, matching standard GFM behaviour of silently ignoring extra cells.

Co-authored-by: Claude Sonnet 4.6 <[email protected]>