feat(skill): add movement acceleration support for skills

1. 新增SMoveComp的isAccelerate字段控制加速逻辑
2. 添加技能配置is_accel字段启用加速效果
3. 实现二次方缓入加速曲线，兼顾起步速度与最终加速度
4. 为6001号技能默认开启加速效果并调整其移动类型为直线运动

assets/script/game/skill/SMoveSystem.ts

@@ -40,10 +40,13 @@ export class SMoveSystem extends ecs.ComblockSystem implements ecs.ISystemUpdate
             return;
         }
         
-        // 根据配置设置移动速度
+        // 根据配置设置移动速度与加速度
         if (skillConfig.speed > 0) {
             moveComp.speed = skillConfig.speed;
         }
+        if (skillConfig.is_accel) {
+            moveComp.isAccelerate = true;
+        }
         
         // 根据runType设置初始位置
         this.initializePosition(moveComp, skillView);
@@ -190,10 +193,12 @@ export class SMoveSystem extends ecs.ComblockSystem implements ecs.ISystemUpdate
         if (moveComp.progress < 1) {
             // 计算下一帧的位置来确定方向
             const nextProgress = Math.min(moveComp.progress + 0.01, 1);
+            const t = moveComp.isAccelerate ? 
+                (nextProgress * nextProgress * 0.7 + nextProgress * 0.3) : 
+                nextProgress;
             const nextPos = v3(0, 0, 0);
             
             // 计算下一个位置
-            const t = nextProgress;
             const oneMinusT = 1 - t;
             const oneMinusTSquared = oneMinusT * oneMinusT;
             const tSquared = t * t;
@@ -245,6 +250,7 @@ export class SMoveHelper {
         if (skillConfig) {
             moveComp.runType = skillConfig.RType || RType.linear;
             moveComp.speed = skillConfig.speed || 500;
+            if (skillConfig.is_accel) moveComp.isAccelerate = true;
         }
     }