feat(plan): add categories query, type, and map helpers (frontend)

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

src/admin/lib/queries/plan.ts

@@ -29,6 +29,30 @@ export interface ResolvedCell {
   rangeTo: string | null;
 }
 
+export interface PlanCategory {
+  id: number;
+  key: string;
+  label: string;
+  color: string;
+  sort_order: number;
+  is_active: boolean;
+}
+
+export const planCategoriesOptions = () =>
+  queryOptions({
+    queryKey: ["plan", "categories"],
+    queryFn: () => jsonQuery<PlanCategory[]>("/api/admin/plan/categories"),
+  });
+
+/** Build a key → category lookup from the categories list. */
+export function categoryMap(
+  categories: PlanCategory[] | undefined,
+): Record<string, PlanCategory> {
+  const map: Record<string, PlanCategory> = {};
+  for (const c of categories ?? []) map[c.key] = c;
+  return map;
+}
+
 /** Czech labels for the plan_category enum — single source of truth shared
  * by the grid chips, the detail view, and aria-labels. */
 export const PLAN_CATEGORIES: ReadonlyArray<{ value: string; label: string }> =
@@ -42,13 +66,14 @@ export const PLAN_CATEGORIES: ReadonlyArray<{ value: string; label: string }> =
     { value: "other", label: "Jiné" },
   ];
 
-const PLAN_CATEGORY_LABELS: Record<string, string> = Object.fromEntries(
-  PLAN_CATEGORIES.map((c) => [c.value, c.label]),
-);
-
-/** Czech label for a plan category, falling back to the raw value. */
-export function planCategoryLabel(value: string): string {
-  return PLAN_CATEGORY_LABELS[value] ?? value;
+/** Czech label for a plan category key, resolved from the loaded categories
+ * map, falling back to the raw key. The `map` arg is optional so callers not
+ * yet threading categories still compile (they show the raw key until wired). */
+export function planCategoryLabel(
+  key: string,
+  map?: Record<string, PlanCategory>,
+): string {
+  return map?.[key]?.label ?? key;
 }
 
 /** Build the display label for a cell's project, preferring the server-