feat(plan): add Sprava kategorii management modal and button

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/admin/pages/PlanWork.tsx

@@ -11,6 +11,7 @@ import {
 import type { PlanCellModalMode } from "../components/PlanCellModal";
 import PlanGrid from "../components/PlanGrid";
 import PlanCellModal from "../components/PlanCellModal";
+import PlanCategoriesModal from "../components/PlanCategoriesModal";
 import Forbidden from "../components/Forbidden";
 import { projectListOptions, type Project } from "../lib/queries/projects";
 import { planCategoriesOptions, type PlanCategory } from "../lib/queries/plan";
@@ -129,6 +130,8 @@ export default function PlanWork() {
   const { data: categoriesData } = useQuery(planCategoriesOptions());
   const categories: PlanCategory[] = categoriesData ?? [];
 
+  const [catModalOpen, setCatModalOpen] = useState(false);
+
   // `lastMutated` is the (userId, date) of the most recent successful
   // mutation. We pass it to PlanGrid as `pulseKey`; the matching cell
   // gets a one-shot CSS pulse animation. We clear it after 700ms (the
@@ -638,6 +641,15 @@ export default function PlanWork() {
             Měsíc
           </button>
         </div>
+        {canEdit && (
+          <button
+            type="button"
+            className="admin-btn admin-btn-secondary"
+            onClick={() => setCatModalOpen(true)}
+          >
+            Správa kategorií
+          </button>
+        )}
       </motion.div>
 
       {gridLoading && (
@@ -695,6 +707,11 @@ export default function PlanWork() {
         onCreateOverrideFromRange={createOverrideFromRange}
         onSwitchToEditRange={switchToEditRange}
       />
+      <PlanCategoriesModal
+        isOpen={catModalOpen}
+        onClose={() => setCatModalOpen(false)}
+        categories={categories}
+      />
     </div>
   );
 }