feat: admin UX improvements — notify buttons, eval config, round finalization

Custom body support for advancement/rejection notification emails, evaluation
config toggle fix, user actions improvements, round finalization with reorder
support, project detail page enhancements, award pool duplicate prevention.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/server/utils/image-upload.ts

@@ -80,7 +80,7 @@ export async function getImageUploadUrl(
   if (!isValidImageType(contentType)) {
     throw new TRPCError({
       code: 'BAD_REQUEST',
-      message: 'Invalid image type. Allowed: JPEG, PNG, GIF, WebP',
+      message: `Invalid image type: "${contentType}". Allowed: JPEG, PNG, GIF, WebP, SVG`,
     })
   }