feat(math): implement m:limLow lower-limit converter

[Abdeltoto]

Closes #2599

Summary

• Implements the \m:limLow\ OMML-to-MathML converter (lower limit, e.g. lim, min, max, inf)
• Maps \m:limLow\ to MathML <munder>\ with base and limit as <mrow>\ children
• Registers the converter in \MATH_OBJECT_REGISTRY\
• Adds 3 unit tests covering standard usage, missing limit, and property element skipping

Spec reference

ECMA-376 Section 22.1.2.54

Test plan

• \�itest run\ passes for omml-to-mathml.test.ts
• Linter and formatter pass (lefthook pre-commit)

Made with Cursor

[caio-pizzol]

hey @Abdeltoto, thanks for the work here! #2771 came in around the same time and handles both this ticket and #2600 in one PR, with more tests. we're going with that one, so closing this as a duplicate.

really appreciate you jumping in — hope to see more contributions from you!