Cold Start

The crawler cave bakes its lighting at demo runtime — generated fresh every run like everything else in the demo.

The director gains a generic preload hook (runs at demo start, content adopted by the part's build). p_tendril preloads the cave's static shell at its distant world center and path-traces lightmaps + a probe field over it while the earlier parts play, so the rock reads baked light the moment the part fades in.

• cave.module: tunnel authors a non-overlapping lightmap UV chart (grid + cap strips); every rock/crystal spawn is a static Model receiver; displacement tessellation is applied separately so a baking caller bakes the base mesh first
• p_tendril: creature + puddles are movable (probe field), follow lights dynamic; bake chain = Lightmap.bakeAll -> VolumeProbe.autoPlace -> tessellation, guarded against double-kick, cancelled on part exit
• director: parts may declare preload(ctx); unadopted preloads are despawned on stop

Source world: 67e6379d-340d-4528-b120-4cbb3f89c134 (Raising Preseed — cave bake)