Spot quote for swapping through a Uniswap V3 pool at the current tick. amountIn is in human units (not wei). zeroForOne=true sends token0 → token1; false sends token1 → token0. Returns amountOut net of the pool's fee tier. NOTE: this is a single-tick spot quote — slippage from depleting concentrated liquidity is NOT modeled. Use for indicative pricing; for production swaps quote against the Uniswap SDK.