feat: add OpenList upload support and upload tasks monitoring page

Backend:
- Add OpenListRecordArtifactUploader implementing AList-compatible API upload
- Add Uploading status to RecordArtifactUploadStatus enum
- Add MarkUploadStarted() to RecordResult entity for upload progress tracking
- Add ListUploadStatus API endpoint with pagination and status filtering
- Add UploadTaskItemDto and UploadTaskListResponse models
- Add upload segment count stats (uploaded/failed/uploading) to session DTO
- Add OpenListUploadSettingsDto and upload target type OpenList

Frontend:
- Add UploadTasksView page with route /upload-tasks
- Add upload status labels and UploadTaskItem types
- Refactor MainLayout navigation and clean up main.css
- Polish DashboardView, MetricCard, StatusBadge, RightDrawer components
- Update SettingsView to support OpenList upload configuration

Build:
- Add frontend/Dockerfile.arm64 for ARM64 frontend image
- Update build-arm64-image.sh script

Other:
- Add segment_completed_openlist.sh trigger script
- Add prototype/ directory with UI mockups
- Add frontend .dockerignore refinements

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/components/ui/MetricCard.vue

@@ -8,78 +8,27 @@ withDefaults(
     description?: string;
     icon?: Component | null;
   }>(),
-  {
-    description: "",
-    icon: null
-  }
+  { description: "", icon: null }
 );
 </script>
 
 <template>
-  <article class="metric-card">
-    <div class="metric-card__header">
-      <span class="metric-card__label">{{ label }}</span>
-      <span v-if="icon" class="metric-card__icon">
-        <el-icon><component :is="icon" /></el-icon>
+  <article class="stat-card">
+    <div class="stat-card__top" style="display:flex;align-items:center;justify-content:space-between">
+      <span class="stat-card__label">{{ label }}</span>
+      <span v-if="icon" class="stat-card__ic">
+        <el-icon :size="18"><component :is="icon" /></el-icon>
       </span>
     </div>
-    <div class="metric-card__value">{{ value }}</div>
-    <div v-if="description" class="metric-card__description">{{ description }}</div>
+    <div class="stat-card__value">{{ value }}</div>
+    <div v-if="description" class="stat-card__hint">{{ description }}</div>
   </article>
 </template>
 
 <style scoped>
-.metric-card {
-  display: grid;
-  gap: 12px;
-  min-height: 164px;
-  padding: 20px;
-  border-radius: 16px;
-  border: 1px solid var(--border-subtle);
-  background:
-    linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(248, 250, 252, 0.98)),
-    var(--surface);
-  box-shadow: var(--shadow-soft);
-}
-
-.metric-card__header {
-  display: flex;
-  align-items: center;
-  justify-content: space-between;
-  gap: 12px;
-}
-
-.metric-card__label {
-  color: var(--text-muted);
-  font-size: 12px;
-  font-weight: 700;
-  letter-spacing: 0.08em;
-  text-transform: uppercase;
-}
-
-.metric-card__icon {
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  width: 38px;
-  height: 38px;
-  border-radius: 12px;
-  background: rgba(37, 99, 235, 0.1);
-  color: var(--accent);
-  font-size: 18px;
-}
-
-.metric-card__value {
-  color: var(--text-primary);
-  font-size: clamp(28px, 2vw, 40px);
-  font-weight: 760;
-  letter-spacing: -0.06em;
-  line-height: 1;
-}
-
-.metric-card__description {
-  color: var(--text-secondary);
-  font-size: 13px;
-  line-height: 1.7;
+.stat-card__top { display: flex; align-items: center; justify-content: space-between; }
+.stat-card__ic {
+  width: 36px; height: 36px; border-radius: 8px; display: grid; place-items: center;
+  background: var(--accent-soft); color: var(--accent);
 }
 </style>