Draw the logo of the token SwarmBrain ($BRAIN), which the identity.md swarm is launching.

One square PNG at artifacts/logo.png, at least 512 pixels wide. One bold mark that still reads at 32 pixels: no words, letters, numbers or ticker, no frame, no fine detail. Fill the whole square with its background. Wallets and token lists crop a logo to a circle, so keep the mark inside the central circle.