Platform review round 2: audit logging migration, nav unification, DB indexes, and UI polish

- Migrate ~41 inline audit log calls to shared logAudit() utility across all routers
- Add transaction-aware prisma parameter to logAudit() for atomic operations
- Unify jury/mentor/observer navigation into shared RoleNav component
- Add composite DB indexes (Evaluation, GracePeriod, AuditLog) for query performance
- Fix profile page: consolidate dual save buttons, proper useEffect initialization
- Enhance auth error page with MOPC branding and navigation
- Improve observer dashboard with prominent read-only badge
- Fix DI-3: fetch projects before bulk status update for accurate notifications
- Remove unused aiBoost field from smart-assignment scoring
- Add shared image-upload utility and structured logger module

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

src/server/routers/live-voting.ts

@@ -1,6 +1,7 @@
 import { z } from 'zod'
 import { TRPCError } from '@trpc/server'
 import { router, protectedProcedure, adminProcedure } from '../trpc'
+import { logAudit } from '../utils/audit'
 
 export const liveVotingRouter = router({
   /**
@@ -227,16 +228,15 @@ export const liveVotingRouter = router({
       })
 
       // Audit log
-      await ctx.prisma.auditLog.create({
-        data: {
-          userId: ctx.user.id,
-          action: 'START_VOTING',
-          entityType: 'LiveVotingSession',
-          entityId: session.id,
-          detailsJson: { projectId: input.projectId, durationSeconds: input.durationSeconds },
-          ipAddress: ctx.ip,
-          userAgent: ctx.userAgent,
-        },
+      await logAudit({
+        prisma: ctx.prisma,
+        userId: ctx.user.id,
+        action: 'START_VOTING',
+        entityType: 'LiveVotingSession',
+        entityId: session.id,
+        detailsJson: { projectId: input.projectId, durationSeconds: input.durationSeconds },
+        ipAddress: ctx.ip,
+        userAgent: ctx.userAgent,
       })
 
       return session
@@ -273,16 +273,15 @@ export const liveVotingRouter = router({
       })
 
       // Audit log
-      await ctx.prisma.auditLog.create({
-        data: {
-          userId: ctx.user.id,
-          action: 'END_SESSION',
-          entityType: 'LiveVotingSession',
-          entityId: session.id,
-          detailsJson: {},
-          ipAddress: ctx.ip,
-          userAgent: ctx.userAgent,
-        },
+      await logAudit({
+        prisma: ctx.prisma,
+        userId: ctx.user.id,
+        action: 'END_SESSION',
+        entityType: 'LiveVotingSession',
+        entityId: session.id,
+        detailsJson: {},
+        ipAddress: ctx.ip,
+        userAgent: ctx.userAgent,
       })
 
       return session