feat(plan): add hard-delete for categories (blocked when in use)

DELETE /plan/categories/:id now hard-deletes the row, guarded: refuses when any live entry/override uses the key (suggests hide instead) and keeps >=1 active category. Modal gains a per-row Smazat with inline confirm. Hiding stays via PATCH is_active.

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

src/routes/admin/plan.ts

@@ -35,7 +35,7 @@ import {
   listPlanCategories,
   createPlanCategory,
   updatePlanCategory,
-  deactivatePlanCategory,
+  deletePlanCategory,
 } from "../../services/planCategory.service";
 
 const MAX_RANGE_DAYS = 92;
@@ -206,14 +206,14 @@ export default async function planRoutes(app: FastifyInstance) {
     },
   );
 
-  // --- DELETE /plan/categories/:id (deactivate) ---
+  // --- DELETE /plan/categories/:id (hard delete; blocked if in use) ---
   app.delete(
     "/categories/:id",
     { preHandler: requirePermission("attendance.manage") },
     async (request: FastifyRequest, reply: FastifyReply) => {
       const id = parseId((request.params as any).id, reply);
       if (id === null) return;
-      const result = await deactivatePlanCategory(id);
+      const result = await deletePlanCategory(id);
       if ("error" in result) return error(reply, result.error, result.status);
       await logAudit({
         request,
@@ -221,9 +221,9 @@ export default async function planRoutes(app: FastifyInstance) {
         action: "delete",
         entityType: "plan_category",
         entityId: id,
-        description: "Kategorie deaktivována",
+        description: "Kategorie smazána",
       });
-      return success(reply, { ok: true }, 200, "Kategorie deaktivována");
+      return success(reply, { ok: true }, 200, "Kategorie smazána");
     },
   );