feat(product-center): implement Figma-designed UI, upload module, and website tests

- Redesign website homepage & product-center per Figma (fonts, logos, hero/footer/customer cases)
- Add API upload module (multer) with static serving for uploads/public assets
- Add OriginGood.delisted flag and SDS request retry logic
- Add admin ImageUpload component and goods import/upload flows
- Add vitest suite for website components and composables (32 tests)
- Add skills, docs, plans and PRODUCT.md

apps/admin/src/layouts/DefaultLayout.vue

@@ -71,11 +71,8 @@ function handleCommand(command: string) {
     <!-- Sidebar -->
     <el-aside :width="collapsed ? '64px' : '240px'" class="layout-aside">
       <div class="brand" :class="{ collapsed }">
-          <div class="brand-mark">IR</div>
-          <div v-if="!collapsed" class="brand-text">
-            <div class="brand-name">Inkreach</div>
-            <div class="brand-tag">官网后台</div>
-          </div>
+        <img src="/logo-unified.svg" class="brand-logo" alt="InkReach" />
+        <span v-if="!collapsed" class="brand-text">印美达官网后台</span>
       </div>
 
       <el-menu
@@ -162,9 +159,9 @@ function handleCommand(command: string) {
 .brand {
   display: flex;
   align-items: center;
-  gap: 10px;
+  gap: 8px;
   height: 56px;
-  padding: 0 16px;
+  padding: 0 20px;
   border-bottom: 1px solid #2b2b33;
   background: #16161a;
   overflow: hidden;
@@ -175,37 +172,18 @@ function handleCommand(command: string) {
   padding: 0;
 }
 
-.brand-mark {
-  flex: 0 0 auto;
-  width: 32px;
-  height: 32px;
-  border-radius: 6px;
-  background: var(--brand-color);
-  color: #fff;
-  font-weight: 700;
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  font-size: 13px;
-  letter-spacing: 0.5px;
+.brand-logo {
+  height: 24px;
+  width: auto;
+  object-fit: contain;
+  flex-shrink: 0;
 }
 
 .brand-text {
-  display: flex;
-  flex-direction: column;
-  line-height: 1.2;
-  white-space: nowrap;
-}
-
-.brand-name {
-  color: #fff;
+  color: #e4e4e7;
+  font-size: 13px;
   font-weight: 600;
-  font-size: 15px;
-}
-
-.brand-tag {
-  color: #9ca3af;
-  font-size: 11px;
+  white-space: nowrap;
 }
 
 .layout-aside :deep(.el-menu) {