systems-power: drawHud, room dimming, right-click input

systems-power

crew-movement: wire input, tick, and render

Add drawCrew to render.go (interpolated circle + selection ring + initial label).
Extend Game with crew slice, walkable-tile map, selectedCrew, and dt-based tick;
handle left-click for crew selection and BFS-path dispatch.

scaffold game loop and placeholder ship render