Type Alias: SpectralType

type SpectralType = "O" | "B" | "A" | "F" | "G" | "K" | "M";

Spectral classification for stellar bodies — Morgan–Keenan single-letter codes. Drives every star-specific derivation (palette, granulation, godrays, tile-reference radius). Lives here because StarIdentity is the canonical user; the physics layer also reads it via StarPhysicsInput.