Fix $not filters on dot-notation paths - #177

$not is a no-op on any field addressed with dot notation. matchFilter(record, { 'person.name': { $not: { $eq: 'Ada' } } }) returns true for every row, Ada included.

matchFilter resolves a field path with resolve(), which splits it on .. The $not branch (src/filter.js line 78 on master) then rebuilds a synthetic record as { [field]: value }, using the whole dotted path as a literal object key. On re-entry resolve() splits that key again, looks for record.person.name inside { 'person.name': value }, gets undefined, and compares undefined against the target. The inner match is therefore always false and the negation always true. Flat field names never hit this because they contain no ..

The fix wraps the already-resolved value under a plain key, { value } and { value: target }, which is the shape matchesNull() uses a few lines below in the same file. Nothing else moves: pathsNeededForFilter still reports the dotted path, and canSkipStats still ignores $not, so row-group and page pruning stay as conservative as before.

Verification. On test/files/hyparquet_struct.parquet, parquetQuery({ file, filter: { 'person.name': { $not: { $eq: 'Ada' } } } }) returned all 4 rows before and returns the 3 non-Ada rows after. The new handles $not with dot-notation case in test/filter.test.js fails on master (expected true to be false) and passes with the change. npx vitest run gives 663 passed in 30 files, npm run lint and npx tsc are clean.