## 1. Implementation
- [ ] 1.1 Update WebSocket auth spec and align server handshake/error messaging with the agreed behavior
- [ ] 1.2 Update optimistic locking conflict response spec and implement standardized payload
- [ ] 1.3 Update workload heatmap defaults (hide_empty, week window) and cache behavior
- [ ] 1.4 Update frontend workload views and API handling if required by new defaults
- [ ] 1.5 Add/adjust tests for WebSocket auth, conflict responses, and workload heatmap defaults