micromark-extension-math's inline closer is code-span logic — any
size-matched $ run closes, backslash-escaped dollars included — so
"$x = \$5$" closed at the escape, errored in KaTeX, and could cascade
into later text. KaTeX itself renders the escaped dollar fine, and its
own auto-render scanner skips escaped dollars, so the author's intent
is unambiguous.
Fix at the render seam (transformMathDelimiters): inside a balanced
inline span, an escaped dollar becomes the dollar-free
\text{\textdollar} before tokenization, with an escape-aware closer
(odd-backslash dollars never close; even-backslash row-break closers
keep closing). Display spans are untouched (a lone $ can't close $$ —
the escape already survives there), prose escaped dollars, code, and
unbalanced spans pass through, and spans without escaped dollars emit
byte-identical text — corpus-verified over 489 dollar-bearing fields
in 40 real sessions (35 changed, all escaped-dollar spans; the
economics session's dollar-amount math now renders).
The latex-testing session's Test-6 question renders 14 KaTeX spans
with zero errors (was 12 + 2 errors). 1578/1578 tests both configs;
typecheck, lint, build, and Electron-runtime smoke green.