SIMD-0391 Stake Program Float to Fixed-Point

Authors: Gabe (Anza), Pete (Anza)

This SIMD proposes replacing all IEEE-754 double-precision floating-point arithmetic within the Solana Stake Program & validator client's warmup/ cooldown logic with a fixed-point implementation using integer arithmetic. The new logic expresses the warmup/cooldown rate in basis points (bps) and performs stake calculations using unsigned 128-bit integers to maintain precision.