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/components/layouts/admin-sidebar.tsx

@@ -244,26 +244,26 @@ export function AdminSidebar({ user }: AdminSidebarProps) {
         <div className="border-t p-3">
           <DropdownMenu>
             <DropdownMenuTrigger asChild>
-              <button className="group flex w-full items-center gap-3 rounded-xl p-2.5 text-left transition-all duration-200 hover:bg-slate-100 dark:hover:bg-slate-800 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring">
+              <button className="group flex w-full items-center gap-3 rounded-xl p-2.5 text-left transition-all duration-200 hover:bg-muted focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring">
                 {/* Avatar */}
                 <div className="relative shrink-0">
                   <UserAvatar user={user} avatarUrl={avatarUrl} size="md" />
                   {/* Online indicator */}
-                  <div className="absolute -bottom-0.5 -right-0.5 h-3 w-3 rounded-full border-2 border-white bg-emerald-500" />
+                  <div className="absolute -bottom-0.5 -right-0.5 h-3 w-3 rounded-full border-2 border-background bg-emerald-500" />
                 </div>
 
                 {/* User info */}
                 <div className="min-w-0 flex-1">
-                  <p className="truncate text-sm font-semibold text-slate-900 dark:text-slate-100">
+                  <p className="truncate text-sm font-semibold text-foreground">
                     {user.name || 'User'}
                   </p>
-                  <p className="truncate text-xs text-slate-500 dark:text-slate-400">
+                  <p className="truncate text-xs text-muted-foreground">
                     {roleLabel}
                   </p>
                 </div>
 
                 {/* Chevron */}
-                <ChevronRight className="h-4 w-4 shrink-0 text-slate-400 transition-transform duration-200 group-hover:translate-x-0.5 group-hover:text-slate-600" />
+                <ChevronRight className="h-4 w-4 shrink-0 text-muted-foreground transition-transform duration-200 group-hover:translate-x-0.5 group-hover:text-foreground" />
               </button>
             </DropdownMenuTrigger>