4‑Layer 100×60 mm PCB – Buck wiring and power nets verified (D3 to U7:VSW/GND, U7:FB to 3V3), IC power rails checked, BOM cleaned (duplicate L5 removed, MPNs standardized, mechanical holes excluded), ERC/DRC re-checked, BOM regenerated, UL 61010 isolation corridor annotations preserved, design BuildReady for manufacturing.