feat: add admin profile editing capability

Added admin endpoint and functionality for editing user profiles from the
report management interface:

Backend Changes:
- Added PUT /api/users/:id endpoint for admin-only profile editing
- Reuses existing updateUserSettings logic with slug uniqueness validation
- Protected with adminGuard and csrfProtection
- Proper audit logging for admin profile edits

Frontend Changes:
- Added adminUpdateUser() method to UserService
- Updated editProfile() in admin-reports to load profile and allow bio editing
- Uses prompt for quick bio editing (can be expanded to full form later)
- Shows success/error toasts and refreshes report list after edit

Admins can now quickly edit reported user profiles directly from the
report management interface.

apps/frontend/src/app/components/admin-reports/admin-reports.component.ts

@@ -1529,10 +1529,30 @@ export class AdminReportsComponent implements OnInit {
 
   editProfile(report: ProfileReportWithUsers): void {
     const userId = report.reportedUser.id;
+    const username = report.reportedUser.username;
 
-    // Navigate to profile page using ObjectId
-    this.router.navigate(['/profile', userId]);
-    this.toastService.success('Navigate to profile to edit');
+    // Load the full profile first to get current values
+    this.userService.getProfile(userId).subscribe({
+      next: (profile) => {
+        const newBio = prompt(`Edit bio for ${username}:`, profile.bio || '');
+
+        if (newBio !== null) {
+          this.userService.adminUpdateUser(userId, { bio: newBio }).subscribe({
+            next: () => {
+              this.toastService.success('Profile updated successfully');
+              this.loadReports();
+              this.closeProfileReviewModal();
+            },
+            error: (err) => {
+              this.toastService.error(err.message ?? 'Failed to update profile');
+            }
+          });
+        }
+      },
+      error: (err) => {
+        this.toastService.error(err.message ?? 'Failed to load profile');
+      }
+    });
   }
 
   makeProfilePrivate(report: ProfileReportWithUsers): void {