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/applicant.ts

@@ -2,6 +2,7 @@ import { z } from 'zod'
 import { TRPCError } from '@trpc/server'
 import { router, publicProcedure, protectedProcedure } from '../trpc'
 import { getPresignedUrl } from '@/lib/minio'
+import { logAudit } from '@/server/utils/audit'
 
 // Bucket for applicant submissions
 export const SUBMISSIONS_BUCKET = 'mopc-submissions'
@@ -205,16 +206,15 @@ export const applicantRouter = router({
         })
 
         // Audit log
-        await ctx.prisma.auditLog.create({
-          data: {
-            userId: ctx.user.id,
-            action: 'CREATE',
-            entityType: 'Project',
-            entityId: project.id,
-            detailsJson: { title: input.title, source: 'applicant_portal' },
-            ipAddress: ctx.ip,
-            userAgent: ctx.userAgent,
-          },
+        await logAudit({
+          prisma: ctx.prisma,
+          userId: ctx.user.id,
+          action: 'CREATE',
+          entityType: 'Project',
+          entityId: project.id,
+          detailsJson: { title: input.title, source: 'applicant_portal' },
+          ipAddress: ctx.ip,
+          userAgent: ctx.userAgent,
         })
 
         return project