Remove BERYLIZE/berylize-pov reference target

Add Preview/Code toggle: real source files from the reference targets

Mark which stages are actually responsible for perceived realism

Give Jessica a Play button: real LLM line + real speech, audio-reactive puppet

Add Test Bench: grid-inspect pipeline stages against real reference implementations

Switch Samantha to NVIDIA NIM (Nemotron 3 Ultra) as primary model

Fix pasted-source bug: actually generate a pipeline instead of relabeling the demo

Ground the expert panel as Samantha: 5-failure-mode audit + tiering

Scaffold LAYER: pipeline node-graph viewer + 4D Avatar Expert