feat: group observer project files by round

Files on the observer project detail page are now grouped by round
(e.g., "Application Intake", "Semi-Finals Document Submission") instead
of shown in a flat list. Uses FileViewer's existing groupedFiles prop.

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

src/server/routers/analytics.ts

@@ -1378,9 +1378,12 @@ export const analyticsRouter = router({
                 id: true, fileName: true, fileType: true, mimeType: true, size: true,
                 bucket: true, objectKey: true, pageCount: true, textPreview: true,
                 detectedLang: true, langConfidence: true, analyzedAt: true,
+                roundId: true,
+                round: { select: { id: true, name: true, roundType: true, sortOrder: true } },
                 requirementId: true,
                 requirement: { select: { id: true, name: true, description: true, isRequired: true } },
               },
+              orderBy: [{ round: { sortOrder: 'asc' } }, { createdAt: 'asc' }],
             },
             teamMembers: {
               include: {
@@ -1526,6 +1529,7 @@ export const analyticsRouter = router({
       return {
         project: {
           ...projectRaw,
+          files: projectRaw.files,
           projectTags,
           teamMembers: teamMembersWithAvatars,
         },