feat(battle-engine): Unity shim members — BoxCollider/RenderTexture/AnimationCurve/Animator (4572->4254)

Add no-op members + supporting types (FilterMode/TextureWrapMode/WrapMode/Keyframe/
AnimatorStateInfo/AnimatorClipInfo) to the UnityEngine shim. Standard Unity API surface,
inferred from frontier member names — Unity types aren't in the decomp so they're
hand-extended, not generated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SVSim.BattleEngine/Shim/UnityEngine/UnityShim.cs

@@ -233,7 +233,7 @@ namespace UnityEngine
     public class ParticleSystemRenderer : Renderer { }
     public class LODGroup : Component { }
     public class Collider : Component { public bool enabled { get; set; } }
-    public class BoxCollider : Collider { }
+    public class BoxCollider : Collider { public Vector3 size { get; set; } public Vector3 center { get; set; } public bool isTrigger { get; set; } }
     public class Rigidbody : Component { }
     public class Rigidbody2D : Component { }
     public class Material : Object
@@ -268,7 +268,13 @@ namespace UnityEngine
     public class Mesh : Object { public Vector3[] vertices { get; set; } public int[] triangles { get; set; } public void Clear() { } public void RecalculateBounds() { } }
     public class Texture : Object { public int width => 0; public int height => 0; }
     public class Texture2D : Texture { public Texture2D(int w, int h) { } public void Apply() { } public Color GetPixel(int x, int y) => Color.white; public void SetPixel(int x, int y, Color c) { } }
-    public class RenderTexture : Texture { public RenderTexture(int w, int h, int depth) { } public RenderTexture(int w, int h, int depth, RenderTextureFormat fmt) { } public void Create() { } public void Release() { } public bool IsCreated() => false; public static RenderTexture active { get; set; } }
+    public enum FilterMode { Point, Bilinear, Trilinear }
+    public enum TextureWrapMode { Repeat, Clamp, Mirror, MirrorOnce }
+    public enum WrapMode { Once = 1, Loop = 2, PingPong = 4, Default = 0, ClampForever = 8, Clamp = 1 }
+    public struct Keyframe { public float time; public float value; public Keyframe(float t, float v) { time = t; value = v; } }
+    public struct AnimatorStateInfo { public bool IsName(string name) => false; public float normalizedTime => 0f; public int shortNameHash => 0; public float length => 0f; }
+    public struct AnimatorClipInfo { public AnimationClip clip => null; public float weight => 0f; }
+    public class RenderTexture : Texture { public RenderTexture(int w, int h, int depth) { } public RenderTexture(int w, int h, int depth, RenderTextureFormat fmt) { } public void Create() { } public void Release() { } public bool IsCreated() => false; public static RenderTexture active { get; set; } public int depth { get; set; } public FilterMode filterMode { get; set; } public TextureWrapMode wrapMode { get; set; } public void DiscardContents() { } public static RenderTexture GetTemporary(int w, int h) => null; public static RenderTexture GetTemporary(int w, int h, int depth) => null; public static RenderTexture GetTemporary(int w, int h, int depth, RenderTextureFormat fmt) => null; public static void ReleaseTemporary(RenderTexture rt) { } }
     public class Sprite : Object { public Rect rect => default; public Texture2D texture => null; public static Sprite Create(Texture2D t, Rect r, Vector2 pivot) => null; }
     public class Shader : Object { public static Shader Find(string n) => null; public bool isSupported => true; }
     public class AnimationClip : Object { public float length => 0f; public string name { get; set; } }
@@ -282,8 +288,12 @@ namespace UnityEngine
         public void Play(string n) { } public void Play(int hash) { }
         public void SetLayerWeight(int layer, float w) { }
         public float speed { get; set; } public bool enabled { get; set; }
+        public void ResetTrigger(string n) { } public void ResetTrigger(int id) { }
+        public void Update(float dt) { }
+        public AnimatorStateInfo GetCurrentAnimatorStateInfo(int layer) => default;
+        public AnimatorClipInfo[] GetCurrentAnimatorClipInfo(int layer) => new AnimatorClipInfo[0];
     }
-    public class AnimationCurve { public float Evaluate(float t) => 0f; }
+    public class AnimationCurve { public float Evaluate(float t) => 0f; public int length => 0; public Keyframe[] keys { get; set; } public WrapMode preWrapMode { get; set; } public WrapMode postWrapMode { get; set; } public static AnimationCurve Linear(float a, float b, float c, float d) => new AnimationCurve(); }
     public class AudioClip : Object { public float length => 0f; }
     public class AudioSource : Component { public AudioClip clip { get; set; } public float volume { get; set; } public bool isPlaying => false; public bool loop { get; set; } public void Play() { } public void Stop() { } public void Pause() { } }
     public class Camera : Component