feat: disable OSNAP by default

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/snap/mod.rs

@@ -96,7 +96,7 @@ impl Default for Snapper {
         enabled.insert(SnapType::Intersection);
         enabled.insert(SnapType::Nearest);
         Self {
-            snap_enabled: true,
+            snap_enabled: false,
             enabled,
             grid_spacing: 1.0,
             snap_radius_px: CROSSHAIR_ARM,