fix: resolve all 15 frontend ESLint errors for green CI

- Replace setState-in-effect with state-based tracking (AdminLayout, EditCategoryModal)
- Convert inline SortIcon component to getSortIcon function (TreeTableView)
- Remove unused catch parameters (CreateCategoryModal, EditCategoryModal)
- Replace `any` types with proper types (SessionFilters, AdminCategoriesPage, SessionHistoryPage)
- Fix unused destructuring variable (StepRatingModal)
- Fix constant binary expression in test (utils.test.ts)

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

frontend/src/components/library/TreeTableView.tsx

@@ -54,7 +54,7 @@ export function TreeTableView({
     onSortChange?.(apiSort)
   }
 
-  const SortIcon = ({ column }: { column: SortColumn }) => {
+  const getSortIcon = (column: SortColumn) => {
     if (sortColumn !== column) return null
     return sortDirection === 'asc' ? (
       <ChevronUp className="h-3.5 w-3.5" />
@@ -79,7 +79,7 @@ export function TreeTableView({
             >
               <div className="flex items-center gap-1">
                 Name
-                <SortIcon column="name" />
+                {getSortIcon('name')}
               </div>
             </th>
             <th className="hidden md:table-cell px-4 py-3 text-left text-sm font-medium text-muted-foreground">
@@ -91,7 +91,7 @@ export function TreeTableView({
             >
               <div className="flex items-center gap-1">
                 Category
-                <SortIcon column="category" />
+                {getSortIcon('category')}
               </div>
             </th>
             <th className="hidden xl:table-cell px-4 py-3 text-left text-sm font-medium text-muted-foreground">
@@ -103,7 +103,7 @@ export function TreeTableView({
             >
               <div className="flex items-center justify-center gap-1">
                 Ver.
-                <SortIcon column="version" />
+                {getSortIcon('version')}
               </div>
             </th>
             <th
@@ -112,7 +112,7 @@ export function TreeTableView({
             >
               <div className="flex items-center justify-center gap-1">
                 Uses
-                <SortIcon column="usage" />
+                {getSortIcon('usage')}
               </div>
             </th>
             <th
@@ -121,7 +121,7 @@ export function TreeTableView({
             >
               <div className="flex items-center gap-1">
                 Updated
-                <SortIcon column="updated" />
+                {getSortIcon('updated')}
               </div>
             </th>
             <th className="px-4 py-3 text-right text-sm font-medium text-muted-foreground">