Bump to 1.42.0

[ww-mw]

Releases the maintainer's 2026-10-18 group G rulings in core (#145, #146, #147).

• Display and typed input follow MATLAB.
  • A complex value with a -0 imaginary part shows +0i; its value and its save keep the -0 (A complex value with a -0 imaginary part shows +0i, and cell literals take signs and imaginary-first members as MATLAB does #146).
  • Cell literals accept a sign with a space after it ({- 2}, {1, - 2}) and imaginary-first members ({i + 1}, {2i - 3}), as MATLAB does. Arithmetic is still refused (A complex value with a -0 imaginary part shows +0i, and cell literals take signs and imaginary-first members as MATLAB does #146).
• An object whose text dictionary holds its properties beside its class is saved as read, in every class (Signal, AliasType, NumericType, LookupTable, ValueType, Breakpoint, ConfigSet, the variant classes and CustomObject). Every edit but a rename is refused with one message, and no editor is offered (An object whose text dictionary holds its properties beside its class is saved as read, in every class #145).
• Writers keep what was read or refuse it (Writers keep what was read or refuse it: no [object Object], MATLAB's 1x1 cell, and host empties that keep their class #147):
  • a hand-edited object of no MATLAB shape is shown as its JSON, and refused in a binary dictionary, instead of [object Object];
  • a 1x1 cell of one element is written with no Dimension in a binary dictionary, as MATLAB writes it;
  • a host's empty string and N-D empties keep their class and size in a text dictionary, and what has no spelling there is refused;
  • a host's empty string at an object's property in a binary dictionary is written as MATLAB's own envelope, which MATLAB reads back as the string.

MATLAB R2027a truth is committed for each MATLAB-facing change. A minor version, since behaviour visible to a host changes (new accepted literals, new refusals).

Gate: npm run verify passed (rc 0). Test files: 294 passed, 1 skipped (295). Tests: 10136 passed, 27 skipped (10163).