Class PanelCoordinator

Set or clear the dataset-browser close handle. Owners populate it when opening the browser and clear it from the browser's own onClose callback.

Set or clear the layers-panel show/hide handle.

Set or clear the control-rail overlay close handle.

Close all open UI panels and overlays in priority order (topmost first):

1. Help overlay
2. Error toast
3. Control-rail flyout / popover
4. Dataset browser
5. Rendering controls
6. Data loading monitor
7. Dimension-slider animation menu + panel
8. Debug console
9. Recording panel
10. Layers panel
11. Performance stats

Each step is guarded so already-hidden panels are no-ops; the existing panels keep the inline original's relative order so any visual "topmost wins" expectation users developed survives.

Escape-key handler with context-aware behavior:

• If the recording panel is currently recording, stop the recording and return — recording takes priority over panel close.
• If we are in fullscreen, do nothing — the browser handles Escape natively to exit fullscreen.
• Otherwise, call closeAll().