Negative remaining balances are shown in a warning treatment; nothing
blocks going over budget.
Applies the Tasks 18-23 design contract: --paper/--ink/--rule/--accent/
--surplus/--overspend tokens and the three type-role font variables in
src/index.css, --font-money on every money figure, and the carry meter
(a 3px hard-stopped gradient beneath each PostTable row) encoding
carried-in surplus, allocation track, spend fill and overrun.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
