test(docmost-client): add unit tests for pure lib modules
Add 230 Vitest unit tests covering the dependency-light, pure modules of
packages/docmost-client/src/lib, imported directly from source:
- node-ops: tree addressing, immutability/clone guarantees, table ops,
throw-vs-noop contracts (87)
- transforms: commentsToFootnotes reading-order renumbering, insertMarkerAfter
mark-preserving split, setCalloutRange regex statefulness (43)
- json-edit: applyTextEdits literal $&/$1, error distinction, immutability (17)
- page-lock: async per-page mutex ordering and error isolation (6)
- filters: filterPage/filterComment truthiness traps, filterSearchResult (19)
- markdown-converter: per-node golden matrix + edge cases (41)
- markdown-document envelope: round-trip, CRLF, malformed-JSON throws (17)
No source files changed. The pre-existing test/markdown-document.test.ts is
left intact; new envelope coverage lives in markdown-document-envelope.test.ts.
Full suite: 16 files / 279 tests green.
cc13c94f53