Most Demanding Phase - Engine Power

**CLI Output Name**: -o mostPowerPhase

**Input**: a flight record file

**Print**: the name of the phase which required the most average engine power: phase_name:Power (W)

Start by locating the Java CLI entry point that handles the -o output options and the code that reads flight record files. Trace how phases and engine power are represented, then implement mostPowerPhase so it prints the phase with the highest average power in the required phase_name:Power (W) format; verify it with a representative flight record.

Written by the indexing model from the issue text.