v0.5.6

Fix monitor focus detection — NSScreen.main was returning Terminal's screen (not the user's actual focused app), causing clicks to be skipped when switching monitors. Replaced with self-tracking of last clicked monitor, correctly handling all 4 focus scenarios:

1. Different monitor focused, cursor elsewhere → move + click ✓
2. Different monitor focused, cursor already there → click only ✓
3. Same monitor focused, cursor elsewhere → move only ✓
4. Same monitor focused, cursor already there → no-op ✓