Fix project detail 500 error and round deletion data integrity

- Add missing migration for FileRequirement table and ProjectFile.requirementId
  column (existed in Prisma schema but had no migration, causing all queries
  with `include: { files: true }` to fail with column not found)
- Make projectTags query resilient with try-catch in project.get
- Reset project status to SUBMITTED when round is deleted (prevents orphaned
  ASSIGNED status after ON DELETE SET NULL nullifies roundId)
- Fix round creation/update to allow requiredReviews=0 for filtering rounds
- Parse Zod validation errors in round creation error display

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

src/server/routers/project.ts

@@ -327,17 +327,21 @@ export const projectRouter = router({
               },
             },
           },
-          projectTags: {
-            include: {
-              tag: {
-                select: { id: true, name: true, category: true, color: true },
-              },
-            },
-            orderBy: { confidence: 'desc' },
-          },
         },
       })
 
+      // Fetch project tags separately (table may not exist if migrations are pending)
+      let projectTags: { id: string; projectId: string; tagId: string; confidence: number; tag: { id: string; name: string; category: string | null; color: string | null } }[] = []
+      try {
+        projectTags = await ctx.prisma.projectTag.findMany({
+          where: { projectId: input.id },
+          include: { tag: { select: { id: true, name: true, category: true, color: true } } },
+          orderBy: { confidence: 'desc' },
+        })
+      } catch {
+        // ProjectTag table may not exist yet
+      }
+
       // Check access for jury members
       if (ctx.user.role === 'JURY_MEMBER') {
         const assignment = await ctx.prisma.assignment.findFirst({
@@ -381,6 +385,7 @@ export const projectRouter = router({
 
       return {
         ...project,
+        projectTags,
         teamMembers: teamMembersWithAvatars,
         mentorAssignment: mentorWithAvatar,
       }