fix: remove redundant edge arrows, flow dash already indicates direction

src/components/TreeFlow.vue

@@ -285,23 +285,6 @@ const svgH = computed(() => containerH.value)
           stroke-width="1"
           stroke-dasharray="5 4"
         />
-        <polygon
-          v-if="edge.points.length >= 2"
-          :points="(() => {
-            const pts = edge.points
-            const last = pts[pts.length - 1]
-            const prev = pts[pts.length - 2]
-            const angle = Math.atan2(last.y - prev.y, last.x - prev.x)
-            const s = 6
-            return [
-              `${last.x + Math.cos(angle) * s} ${last.y + Math.sin(angle) * s}`,
-              `${last.x + Math.cos(angle + 2.5) * s} ${last.y + Math.sin(angle + 2.5) * s}`,
-              `${last.x + Math.cos(angle - 2.5) * s} ${last.y + Math.sin(angle - 2.5) * s}`,
-            ].join(' ')
-          })()"
-          :fill="edge.visited ? '#e0c060' : '#333'"
-          :filter="edge.visited ? 'url(#edge-glow)' : ''"
-        />
       </g>
     </svg>