RFC-0028: Render Frame Consistency

Status: Normative. RenderFrameId=(world_version:u64,render_time_ns:i64,sequence:u64). Renderer acquires an immutable declared WorldVersion; all passes and resource reads for one frame use it. Interpolation names both source ticks. Culling/LOD are representational and cannot mutate authority. Present is external IO and returns input/events through a later explicit transaction.