Fix CT window number inputs and update Liver preset

[aperson30]

What

Fixes the Brightness/Contrast number inputs in the viewer's CT window panel and tweaks the Liver preset default.

Changes

• Sync number boxes to the active window. The Brightness/Contrast number inputs were only seeded once on mount, so switching CT window presets (Soft Tissue/Bone/Lung/Liver) moved the sliders but left the number boxes stale. They now re-sync via useEffect whenever the window changes.
• Apply on blur. Typing a Brightness/Contrast value now takes effect when you click off the field, not only when you press Enter (same clamping as before).
• Liver preset default → Brightness 50 / Contrast 150 (width: 150, center: -50).

Notes

• Brightness is the negated window center; the number box now matches the slider (both negated), fixing a prior textbox/slider mismatch.