#52 docs(workflows): require React verification for function support

Summary

Make React rendering verification explicit when adding function support, including cases where the generic renderer needs no TSX change.

Function support → choose generic or special MathML → verify rendered output

Require schema-parsed renderer fixtures and checks for argument counts, operand order, grouping, substitutions and empty calls.

Evidence

• Before: the workflow suggested generic renderer reuse without an explicit React completion criterion.
• After: steps 3 and 4 require rendered evidence and targeted notation regressions.
• All 15 local documentation links resolve; git diff --check passed.
• Documentation only; runtime tests were not rerun.

Merge Danger

Door: two-way. Documentation can be reverted.

Blast Radius: guidance. Changes the function-support workflow; no runtime behavior changes.