Money Is Integer Minor Units; Ledger Requests Are Two-Decimal for Now

Context

Approval compares an exact integer difference and later batch accounting has a temporary exponent restriction.

Decision

Represent reconciliation money in exact integer minor units and restrict nonempty accounting plans to two-decimal currencies for now.

Alternatives Considered

Use floating-point decimal arithmetic for reconciliation. Float rounding would weaken the exact-zero financial comparison.

Permit every exponent before adapting batch accounting. Current request conversion could misstate non-two-decimal values.

Consequences

Balance uses exact equality without tolerance. The current console formats US dollars and parses cents regardless of currency, which requires correction. An empty accounting plan bypasses the exponent check; other plans remain restricted.