Add configurable cursor deadzone (0-15 degrees)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YVREx3uo7nz1FEhzveWTUh

src/main/java/dev/lumareth/improvedAerodynamics/flight/CursorPilot.java

@@ -53,6 +53,14 @@ final class CursorPilot {
         // Cursor as angles from the reticle: sideways (positive right) and up, both through any 270 degree cone
         double sideways = Math.atan2(aim.cr(), aim.cf());
         double vertical = Math.atan2(aim.cu(), Math.hypot(aim.cf(), aim.cr()));
+        // Deadzone around the reticle: shrink the cursor offset by its radius, direction kept
+        double offset = Math.hypot(sideways, vertical);
+        double deadzone = Math.toRadians(CursorAimConfig.DEADZONE_DEGREES.get());
+        if (offset > 1.0E-9) {
+            double scale = Math.max(0.0, offset - deadzone) / offset;
+            sideways *= scale;
+            vertical *= scale;
+        }
         double lateral = saturate(sideways / fullAngle);
         double blend = smoothstep(Math.abs(sideways), FINE_START, FINE_END);