Add adjustable pointer movement sizes

[enaboapps]

Summary

• add persisted pointer movement multipliers for small, medium, and large profiles
• add Settings > Pointer sliders with a three-lane animated preview
• apply multipliers to pointer profile recommendations and PC-side movement execution

Behavior

• defaults preserve current movement behavior
• values normalize to 50-200% in 5% steps
• Android protocol remains unchanged
• connected clients pick up new profile values on the next pointer profile request/reconnect

Tests

• npm test -- src/shared/pointer-movement-settings.test.ts src/main/pointer-movement-settings-store.test.ts src/main/pointer-movement-settings-ipc.test.ts src/main/input/pointer-profile.test.ts src/main/input/libnut-win32-adapter.test.ts
• npm test
• npm run build

Closes #243