Refactor regex handling and improve null checks across various components

Updated regex patterns in episode parsing and metadata handling to use String.raw for better readability and maintainability. Enhanced null checks in BlockBuilder, MediaPanel, and ShowMetadataCard components to prevent potential runtime errors. Consolidated imports in UsersPanel for cleaner code structure.

frontend/src/features/admin/users/UsersPanel.tsx

@@ -14,8 +14,7 @@ import { useTableSort } from '@/shared/lib/table-sort'
 import { SortHeader } from '@/shared/ui/sortable'
 import { toast } from '@/shared/ui/toast-store'
 import type { UserSummaryDto } from '@/shared/api/types'
-import { changeUserRole } from '@/features/admin/roles/api'
-import { listRoles } from '@/features/admin/roles/api'
+import { changeUserRole, listRoles } from '@/features/admin/roles/api'
 import { blockUser, createUser, deleteUser, listUsers, resetUserPassword, unblockUser } from './api'
 
 const PAGE_SIZE = 20