Principles
- Canvas time is always visible. LIVE pill or REPLAY timestamp never hides, truncates, or covers.
- The focal canvas is never blocked without operator intent. The right rail pushes; modals are forbidden in the focal zone.
- Critical alerts are immediate and motionless. No slide-in, no fade. Motion implies optional; P1 is not optional.
- Every status uses shape + color. Color alone is never a signal.
- No more than 7 visible chrome surfaces. Sidebar, top bar, tabs, canvas, rail, timeline, toasts — that's the budget.
- Density is a persistent operator preference. Stored per account, not session.
- Destructive actions require exactly one-step confirm. No double modals; no zero-step.
- Every non-obvious state surfaces a "why" tooltip. The text answers "why," not "what."
- Keyboard nav is a first-class workflow. Command palette (Cmd+K) reaches every action.
- Shift handoff state persists every 30s. The incoming operator sees the outgoing operator's working state.