feat: enhance sidebar quota display with progress bar and improve upload modal UX

- Replace percentage-based quota with point-based display in sidebar
- Add visual progress bar for remaining quota with gradient styling
- Implement upload progress tracking in material upload modal
- Add loading indicators and progress information during file uploads
- Prevent modal interaction while uploading by disabling close controls
- Show current upload status including file index and completion percentage

frontend/app/web-gold/src/components/SidebarNav.vue

@@ -66,7 +66,12 @@ const remainingPercent = computed(() => {
     >
       <div class="user-card">
         <div class="user-card__mobile">{{ maskedMobile }}</div>
-        <div class="user-card__quota">剩余额度 {{ remainingPercent }}%</div>
+        <div class="user-card__quota">
+          <span>剩余额度 {{ userStore.remainingPoints }} 点</span>
+          <div class="quota-progress">
+            <div class="quota-progress__bar" :style="{ width: remainingPercent + '%' }"></div>
+          </div>
+        </div>
       </div>
     </router-link>
   </aside>
@@ -187,4 +192,33 @@ const remainingPercent = computed(() => {
   font-size: 12px;
   color: var(--color-text-secondary);
 }
+
+.quota-progress {
+  margin-top: 6px;
+  height: 6px;
+  background: var(--color-gray-100);
+  border-radius: 3px;
+  overflow: hidden;
+  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.06);
+}
+
+.quota-progress__bar {
+  height: 100%;
+  background: linear-gradient(90deg, #3b82f6, #60a5fa);
+  border-radius: 3px;
+  transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
+  position: relative;
+  box-shadow: 0 1px 3px rgba(59, 130, 246, 0.4);
+}
+
+.quota-progress__bar::after {
+  content: '';
+  position: absolute;
+  top: 0;
+  left: 0;
+  right: 0;
+  height: 50%;
+  background: linear-gradient(180deg, rgba(255, 255, 255, 0.3), transparent);
+  border-radius: 3px 3px 0 0;
+}
 </style>