style(logo): 去掉 V 字，改为光圈+播放三角标

光圈内放播放三角（呼应图像+视频），快门点改黄色墨边小圆，
整体更几何、更贴合 Memphis 风格。

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

frontend/src/components/Logo.vue

@@ -1,8 +1,8 @@
 <script setup>
-// Vivid mark: an open spectrum ring (lens/aperture) around a folded "V", with a
+// Vivid mark: an open spectrum ring (lens/aperture) around a play triangle,
-// shutter dot closing the gap — image + video in one glyph. Transparent
+// with a shutter dot closing the gap — image + video in one glyph.
-// background so it reads on both the dark and light shells. Colors follow the
+// Transparent background so it reads on both the dark and light shells.
-// memphis crayon palette (orange / pink / blue).
+// Colors follow the memphis crayon palette (orange / pink / blue).
 // Each instance gets unique gradient ids (useId) so multiple logos on one
 // page don't share/clobber defs.
 import { useId } from 'vue'
@@ -11,7 +11,6 @@ defineProps({ size: { type: [Number, String], default: 40 } })
 
 const uid = useId()
 const gRing = `vring-${uid}`
-const gV = `vv-${uid}`
 </script>
 
 <template>
@@ -23,20 +22,17 @@ const gV = `vv-${uid}`
         <stop offset="0.5" stop-color="#f472b6" />
         <stop offset="1" stop-color="#38bdf8" />
       </linearGradient>
-      <linearGradient :id="gV" x1="14" y1="14" x2="34" y2="34" gradientUnits="userSpaceOnUse">
-        <stop stop-color="#f97316" />
-        <stop offset="1" stop-color="#ec5b13" />
-      </linearGradient>
     </defs>
 
     <g transform="translate(24 24)">
       <!-- open ring: dash gap leaves room for the shutter dot -->
-      <circle r="18.5" fill="none" :stroke="`url(#${gRing})`" stroke-width="3.2"
+      <circle r="17.5" fill="none" :stroke="`url(#${gRing})`" stroke-width="4.4"
-              stroke-linecap="round" stroke-dasharray="86 30" transform="rotate(-58)" />
+              stroke-linecap="round" stroke-dasharray="84 32" transform="rotate(-58)" />
-      <!-- folded V -->
+      <!-- play triangle = image + video -->
-      <path d="M-8 -7.5 L0 9 L8 -7.5" fill="none" :stroke="`url(#${gV})`" stroke-width="4.8"
+      <path d="M-3 -6.5 L8.5 0 L-3 6.5 Z" fill="#ec5b13" stroke="#111" stroke-width="1.4"
-            stroke-linecap="round" stroke-linejoin="round" />
+            stroke-linejoin="round" />
-      <circle cx="13" cy="-13" r="3.4" fill="#ec5b13" />
+      <!-- shutter dot -->
+      <circle cx="13" cy="-13" r="4.2" fill="#fef08a" stroke="#111" stroke-width="1.6" />
     </g>
   </svg>
 </template>