Regulated 12 V 3 A Magneto Circuit

I’m looking for a complete design of a magneto-based power-supply module that takes a 6–12 V AC input from the magneto coil and delivers a steady 12 V DC at 3 A. The unit will sit inside an enclosure in a controlled indoor setting, so you won’t need to factor in extreme temperature or moisture, but space is limited to roughly 5 cm × 10 cm.

Your solution must include reliable regulation—low ripple, solid transient response, and protection against over-voltage or short-circuit events. If you prefer linear regulation, switch-mode, or a hybrid approach, feel free to choose what best meets efficiency and thermal targets; just be ready to justify that choice with calculations or simulation data.

Please provide:
• Schematic with component values
• Bill of materials with part numbers that are readily available
• PCB layout (Gerber or native KiCad/Altium files) sized to fit within 5 × 10 cm
• Simulation or bench-test evidence showing it can hold 12 V DC at 3 A from any point in the 6–12 V input range

I’ll review functionality, thermal performance, and ease of sourcing before sign-off, so clear documentation is essential.