feat: 实现抓墙高度记忆、背墙跳/对墙跳、蹬墙后自动抓墙

- PlayerController: 添加 wallGrabY/wallGrabDir/isPostWallJump 字段及 API
- WallSlideState: 高度限制（超限强制下滑不可蹬跳）+ 静止悬挂 + 反向键释放
- WallJumpState: 区分背墙跳(WallJumpAwayForce)/对墙跳(WallJumpBackForce)
  蹬墙后标记 PostWallJump 允许空中自动抓墙；恢复空中冲刺次数
- FallState/JumpState: 新增抓墙入口（朝向按键 OR PostWallJump 自动抓墙）
- PlayerMovement.WallJump: 增加 jumpAway 参数区分两种跳跃力
- IdleState/RunState: 落地时重置抓墙记录和蹬墙跳标记

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Assets/_Game/Scripts/Player/States/FallState.cs

@@ -64,6 +64,20 @@ namespace BaseGames.Player.States
                 return;
             }
 
+            // ── 抓墙：贴墙 + 朝向墙壁按键，或蹬墙跳后的自动抓墙──────────────
+            var wd = Owner.WallDetector;
+            if (wd != null && wd.IsTouchingWall)
+            {
+                int wallDir = wd.WallDirection;
+                bool pressingTowardWall = Mathf.Abs(Input.MoveInput.x) > 0.01f
+                                          && (int)Mathf.Sign(Input.MoveInput.x) == wallDir;
+                if (pressingTowardWall || Owner.IsPostWallJump)
+                {
+                    _owner.TransitionTo(_owner.GetState<WallSlideState>());
+                    return;
+                }
+            }
+
         }
 
         public override void OnStateFixedUpdate()