feat(aigc): refine generation UI and add task status tracking

Add real-time task status polling for active generation jobs.
Overhaul GeneratingProgressPanel with dynamic step indicators, action buttons and updated styling.
Update PointInsufficientDialog to show detailed credit balance and usage summary.
Fix RecordCard media display and status logic for generating and completed tasks.
Restyle PhotoPickDrawer and update its instructional copy.
Add overflow styling for generating template content container.

src/pages-aigc/useTemplate/styles/index.scss

@@ -31,6 +31,11 @@
   box-sizing: border-box;
 }
 
+.aigc-use-template-content.is-generating {
+  overflow-y: auto;
+  padding: 12px 12px 16px;
+}
+
 .aigc-use-template-popup-host {
   position: fixed;
   z-index: 30;