Comprehensive platform review: security fixes, query optimization, UI improvements, and code cleanup

Security (Critical/High):
- Fix path traversal bypass in local storage provider (path.resolve + prefix check)
- Fix timing-unsafe HMAC comparison (crypto.timingSafeEqual)
- Add auth + ownership checks to email API routes (verify-credentials, change-password)
- Remove hardcoded secret key fallback in local storage provider
- Add production credential check for MinIO (fail loudly if not set)
- Remove DB error details from health check response
- Add stricter rate limiting on application submissions (5/hour)
- Add rate limiting on email availability check (anti-enumeration)
- Change getAIAssignmentJobStatus to adminProcedure
- Block dangerous file extensions on upload
- Reduce project list max perPage from 5000 to 200

Query Optimization:
- Optimize analytics getProjectRankings with select instead of full includes
- Fix N+1 in mentor.getSuggestions (batch findMany instead of loop)
- Use _count for files instead of fetching full file records in project list
- Switch to bulk notifications in assignment and user bulk operations
- Batch filtering upserts (25 per transaction instead of all at once)

UI/UX:
- Replace Inter font with Montserrat in public layout (brand consistency)
- Use Logo component in public layout instead of placeholder
- Create branded 404 and error pages
- Make admin rounds table responsive with mobile card layout
- Fix notification bell paths to be role-aware
- Replace hardcoded slate colors with semantic tokens in admin sidebar
- Force light mode (dark mode untested)
- Adjust CardTitle default size
- Improve muted-foreground contrast for accessibility (A11Y)
- Move profile form state initialization to useEffect

Code Quality:
- Extract shared toProjectWithRelations to anonymization.ts (removed 3 duplicates)
- Remove dead code: getObjectInfo, isValidImageSize, unused batch tag functions, debug logs
- Remove unused twilio dependency
- Remove redundant email index from schema
- Add actual storage object deletion when file records are deleted
- Wrap evaluation submit + assignment update in
- Add comprehensive platform review document

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

src/server/routers/evaluation.ts

@@ -196,21 +196,21 @@ export const evaluationRouter = router({
         })
       }
 
-      // Submit
-      const updated = await ctx.prisma.evaluation.update({
-        where: { id },
-        data: {
-          ...data,
-          status: 'SUBMITTED',
-          submittedAt: now,
-        },
-      })
-
-      // Mark assignment as completed
-      await ctx.prisma.assignment.update({
-        where: { id: evaluation.assignmentId },
-        data: { isCompleted: true },
-      })
+      // Submit evaluation and mark assignment as completed atomically
+      const [updated] = await ctx.prisma.$transaction([
+        ctx.prisma.evaluation.update({
+          where: { id },
+          data: {
+            ...data,
+            status: 'SUBMITTED',
+            submittedAt: now,
+          },
+        }),
+        ctx.prisma.assignment.update({
+          where: { id: evaluation.assignmentId },
+          data: { isCompleted: true },
+        }),
+      ])
 
       // Audit log
       await ctx.prisma.auditLog.create({