rust_decimal — Exact Decimal Arithmetic

rust_decimal — fixed-point decimal arithmetic for Rust. 128-bit signed decimal, exact (no float rounding errors), suitable for finance, currency, Bitcoin sat ↔ fiat conversions, accounting. Up to 28 significant digits, arithmetic preserves precision. Includes RoundingStrategy for explicit truncation/rounding control. Integrates with serde, sqlx, postgres. USE WHEN: user mentions "rust_decimal", "Decimal", "dec!", "RoundingStrategy", "no float", "exact arithmetic", "fixed-point Rust", "currency math Rust", "sat to fiat conversion" DO NOT USE FOR: Crypto primitives - use `security/libsodium` or `bitcoin/cryptography/*` DO NOT USE FOR: BigInteger / arbitrary-precision math…