anyel1to/ATSMATRIX-SWARM ? reverse-engineered prompt

Build me a smooth browser based swarm simulation that shows hundreds of little agents moving like a flock in real time. I want the usual boids behavior, so they separate when they get too close, align with nearby agents, and drift toward the group, with a clean visual style and motion trails.

It should run entirely in the browser with no heavy framework and feel fast even at higher agent counts. Add a pointer force field so I can attract or repel the swarm with the mouse, and let me toggle that mode, pause and resume, turn trails on and off, reset the simulation, and switch between a few population sizes with keyboard shortcuts and simple on screen controls.

Please make it a single page app with a canvas based animation, a small HUD showing useful stats, and a basic local dev server so I can run it easily. If you need current docs for anything, look them up online first.