Completed brainstorming session. Design includes:
- 1-bit SM/CM token split replacing old 2-bit type field
- IRAMWriteToken replacing SysToken/CfgToken hierarchy
- SM T0/T1 memory tier split with shared T0 storage
- EXEC opcode for bootstrap and bulk token injection
- 5 implementation phases

fixed sm isntruction return construction bug

- Replace dagre with cytoscape-elk for proper layered graph layout
- Add post-layout edge routing that curves skip connections around
intermediate nodes with staggered offsets to prevent crossovers
- Fixed-size 40px circular nodes with thin coloured borders
- Thin 1px black edges with small arrows
- Add Playwright browser env vars to flake.nix for NixOS