Introduce background spawning with parallax effect (#86)

Co-authored-by: Michal Pikulski <michal.a.pikulski@gmail.com>
Reviewed-on: #86

Assets/Scripts/Minigames/Airplane/Data/PrefabSpawnEntryComponent.cs

@@ -0,0 +1,27 @@
+using Minigames.Airplane.Data;
+using UnityEngine;
+
+namespace Minigames.Airplane.Data
+{
+    /// <summary>
+    /// Component to store spawn positioning data on prefabs.
+    /// Attach this to obstacle prefabs that need specific positioning behavior.
+    /// If not present, spawner will use default positioning from AirplaneSettings.
+    /// </summary>
+    [AddComponentMenu("Airplane/Prefab Spawn Entry")]
+    public class PrefabSpawnEntryComponent : MonoBehaviour
+    {
+        [Tooltip("How to position this object vertically")]
+        public SpawnPositionMode spawnPositionMode = SpawnPositionMode.SnapToGround;
+        
+        [Tooltip("Y position to use (when mode is SpecifiedY)")]
+        public float specifiedY;
+        
+        [Tooltip("Min Y for random range (when mode is RandomRange)")]
+        public float randomYMin = -5f;
+        
+        [Tooltip("Max Y for random range (when mode is RandomRange)")]
+        public float randomYMax = 5f;
+    }
+}
+