The compact placement is complete. I’m reconciling the final coordinates and independently checking the 20×40 mm outline, component access, and placement DRC.
Created a compact 20 × 40 mm, 2-layer PCB and placed all components on top:
LED centered at the front edge
Battery connector centered at the rear
Slide switch accessible along the side
Resistor positioned beside the LED
Placement verification found no overlaps, out-of-bounds parts, or keepout violations. Three expected airwires remain because routing was not requested.