feat: 实现飞白笔触效果，settling阶段根据速度方向绘制墨迹拖尾

src/components/effects/ink-data-morph.tsx

@@ -189,6 +189,8 @@ function updateParticle(p: Particle, maxTrail: number): void {
       }
     }
 
+    p.prevVx = p.vx;
+    p.prevVy = p.vy;
     p.x += p.vx;
     p.y += p.vy;
     p.vx *= 0.98;
@@ -377,6 +379,43 @@ function drawInkLayers(
   }
 }
 
+function drawFeibai(
+  ctx: CanvasRenderingContext2D,
+  p: Particle,
+  rgb: string,
+): void {
+  const speed = Math.sqrt(p.prevVx * p.prevVx + p.prevVy * p.prevVy);
+  if (speed < 0.1) {
+    return;
+  }
+
+  const dirX = -p.prevVx / speed;
+  const dirY = -p.prevVy / speed;
+  const length = p.radius * (3 + Math.random() * 2);
+  const endX = p.x + dirX * length;
+  const endY = p.y + dirY * length;
+
+  const perpX = -dirY;
+  const perpY = dirX;
+  const curvature = (Math.random() - 0.5) * length * 0.15;
+  const cpX = (p.x + endX) / 2 + perpX * curvature;
+  const cpY = (p.y + endY) / 2 + perpY * curvature;
+
+  const grad = ctx.createLinearGradient(p.x, p.y, endX, endY);
+  grad.addColorStop(0, `rgba(${rgb}, ${p.opacity * 0.25})`);
+  grad.addColorStop(1, 'transparent');
+
+  ctx.save();
+  ctx.lineCap = 'round';
+  ctx.beginPath();
+  ctx.moveTo(p.x, p.y);
+  ctx.quadraticCurveTo(cpX, cpY, endX, endY);
+  ctx.strokeStyle = grad;
+  ctx.lineWidth = Math.max(0.3, p.radius * 0.6);
+  ctx.stroke();
+  ctx.restore();
+}
+
 function drawParticle(
   ctx: CanvasRenderingContext2D,
   p: Particle,
@@ -400,6 +439,9 @@ function drawParticle(
     drawInkLayers(ctx, p, config);
   } else if (p.phase === 'settling') {
     drawInkLayers(ctx, p, config);
+    if (config.showFeibai) {
+      drawFeibai(ctx, p, rgb);
+    }
   } else if (p.phase === 'fading') {
     const grad1 = ctx.createRadialGradient(p.x, p.y, 0, p.x, p.y, r * 1.5);
     grad1.addColorStop(0, `rgba(${rgb}, ${p.opacity * 0.6})`);