Harvest Cameron's answer to Tangled issue #1. Knowledge tokens are ivory-mercury slugs: opaque bone-white liquid, restrained self-glow, discrete viscous slugs merging into a taut pool, filament-snap at sinks. Rejected: hollow facet, continuous ribbon, pearl train. The exposure half is deliberately deferred: Cameron wants to reconsider the exposure mechanic itself before binding a surface treatment, so the angular-contour-versus-smooth-pool call stays [OPEN - issue #1] and final exposure/attention art holds. Knowledge and demand token art unblocked (ROADMAP #33 frontend-only slice). Docs only; no sim or renderer behavior change.