feat(aigc/useTemplate): add multi-step template generation confirmation workflow

- add PhotoConfirmDrawer component for post-photo-pick quality verification
- add GenerateConfirmPanel to display generation point cost and available balance
- extend TemplateVersionHero to support custom variant styles
- refactor useTemplate page to use step-based workflow flow

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

@@ -28,7 +28,7 @@
   height: 100%;
   min-height: 0;
   overflow: hidden;
-  padding: 24px 18px;
+  padding: 18px;
   box-sizing: border-box;
 }