Release 1.2.0: window animation and 0 pt spacing

[StevenACZ]

Summary

• Windows glide into place on shortcut, undo and restore moves (about 0.22 s, display-paced up to 120 Hz). A new "Animate windows" setting turns it off; Reduce Motion and moves to another display stay instant. Each frame picks the size/position write order that keeps visible edges from stepping back.
• Window spacing now defaults to 0 pt; an existing spacing is kept.
• A window that its app keeps larger than a bottom zone is lifted back inside the screen.
• Move warnings dismiss themselves after 6 s.
• Preferences icons share one column, including the Updates header; the spacing slider sits beside its label.

Validation

• make check: lint, 123 tests, signed Release bundle.
• Apple Silicon QA: animations end on the exact target frame, a new shortcut lands the running animation first, idle CPU returns to 0.0%, and bottom zones keep Finder and Chrome on screen.