updated stars in game play grid

src/graphics/effects/Starfield3D.cpp

@@ -23,6 +23,22 @@ void Starfield3D::resize(int w, int h) {
     centerY = height * 0.5f;
 }
 
+void Starfield3D::setMagnetTarget(float localX, float localY, float strength) {
+    if (strength <= 0.0f) {
+        clearMagnetTarget();
+        return;
+    }
+    magnetActive = true;
+    magnetStrength = strength;
+    magnetX = std::clamp(localX, 0.0f, static_cast<float>(width));
+    magnetY = std::clamp(localY, 0.0f, static_cast<float>(height));
+}
+
+void Starfield3D::clearMagnetTarget() {
+    magnetActive = false;
+    magnetStrength = 0.0f;
+}
+
 float Starfield3D::randomFloat(float min, float max) {
     std::uniform_real_distribution<float> dist(min, max);
     return dist(rng);
@@ -147,13 +163,24 @@ void Starfield3D::drawStar(SDL_Renderer* renderer, float x, float y, SDL_Color c
 }
 
 void Starfield3D::draw(SDL_Renderer* renderer, float offsetX, float offsetY, float alphaScale, bool grayscale) {
+    const bool useMagnet = magnetActive && magnetStrength > 0.0f;
     for (const Star3D& star : stars) {
         // Calculate perspective projection factor
         const float k = DEPTH_FACTOR / star.z;
         
         // Calculate screen position with perspective
-        const float px = star.x * k + centerX;
-        const float py = star.y * k + centerY;
+        float px = star.x * k + centerX;
+        float py = star.y * k + centerY;
+
+        if (useMagnet) {
+            float dx = magnetX - px;
+            float dy = magnetY - py;
+            float dist = std::sqrt(dx * dx + dy * dy);
+            float pull = magnetStrength / (magnetStrength + dist + 1.0f);
+            pull = std::clamp(pull, 0.0f, 0.35f);
+            px += dx * pull;
+            py += dy * pull;
+        }
         
         // Only draw stars that are within the viewport
         if (px >= 0.0f && px <= static_cast<float>(width) &&