Multi-role members, round detail UI overhaul, dashboard jury progress, and submit bug fix

- Add roles UserRole[] to User model with migration + backfill from existing role column
- Update auth JWT/session to propagate roles array with [role] fallback for stale tokens
- Update tRPC hasRole() middleware and add userHasRole() helper for inline role checks
- Update ~15 router inline checks and ~13 DB queries to use roles array
- Add updateRoles admin mutation with SUPER_ADMIN guard and priority-based primary role
- Add role switcher UI in admin sidebar and role-nav for multi-role users
- Remove redundant stats cards from round detail, add window dates to header banner
- Merge Members section into JuryProgressTable with inline cap editor and remove buttons
- Reorder round detail assignments tab: Progress > Score Dist > Assignments > Coverage > Jury Group
- Make score distribution fill full vertical height, reassignment history always open
- Add per-juror progress bars to admin dashboard ActiveRoundPanel for EVALUATION rounds
- Fix evaluation submit bug: use isSubmitting state instead of startMutation.isPending

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

prisma/schema.prisma

@@ -303,6 +303,7 @@ model User {
   name           String?
   emailVerified  DateTime? // Required by NextAuth Prisma adapter
   role           UserRole   @default(JURY_MEMBER)
+  roles          UserRole[] @default([])
   status         UserStatus @default(INVITED)
   expertiseTags  String[]   @default([])
   maxAssignments Int? // Per-round limit