Enhance audience management features with new components and API integrations

- Added `AssignCoursesModal`, `AudienceMemberRow`, `AudienceTable`, and related components for improved audience management UI.
- Implemented audience invite actions including resend and revoke functionality.
- Updated audience API to support importing members and assigning courses.
- Refactored audience data handling to include status and invite management.
- Improved overall user experience with pagination and selection features in the audience table.

apps/dashboard/src/lib/features/course/utils/constants.ts

@@ -16,8 +16,51 @@ export const EXERCISE_TEMPLATE_TAGS = {
   GIT: 'GIT'
 };
 
+/** Named sort keys for course lists (URL `sort`, localStorage, filter UI). */
+export const CourseSortBy = {
+  DateCreated: 'date_created',
+  Published: 'published',
+  Lessons: 'lessons'
+} as const;
+
+export type CourseSortBy = (typeof CourseSortBy)[keyof typeof CourseSortBy];
+
+export const DEFAULT_COURSE_SORT: CourseSortBy = CourseSortBy.DateCreated;
+
+/** URL `order` param and filter toggle (ascending vs descending). */
+export const CourseSortOrder = {
+  Asc: 'asc',
+  Desc: 'desc'
+} as const;
+
+export type CourseSortOrder = (typeof CourseSortOrder)[keyof typeof CourseSortOrder];
+
+export const DEFAULT_SORT_ORDER: CourseSortOrder = CourseSortOrder.Desc;
+
+const COURSE_SORT_ORDER_VALUES = new Set<string>(Object.values(CourseSortOrder));
+
+export function parseCourseSortOrder(value: string | null | undefined): CourseSortOrder {
+  if (value != null && COURSE_SORT_ORDER_VALUES.has(value)) {
+    return value as CourseSortOrder;
+  }
+  return DEFAULT_SORT_ORDER;
+}
+
 export const COURSE_SORT_OPTIONS = [
-  { value: '0', label: 'courses.course_filter.date_created' },
-  { value: '1', label: 'courses.course_filter.published' },
-  { value: '2', label: 'courses.course_filter.lessons' }
+  { value: CourseSortBy.DateCreated, label: 'courses.course_filter.date_created' },
+  { value: CourseSortBy.Published, label: 'courses.course_filter.published' },
+  { value: CourseSortBy.Lessons, label: 'courses.course_filter.lessons' }
 ] as const;
+
+const COURSE_SORT_VALUES = new Set<string>(Object.values(CourseSortBy));
+
+/** Parses URL `sort` / stored sort strings into {@link CourseSortBy}; unknown values fall back to default. */
+export function parseCourseSortValue(value: string | null | undefined): CourseSortBy {
+  if (value == null || value === '') {
+    return DEFAULT_COURSE_SORT;
+  }
+  if (COURSE_SORT_VALUES.has(value)) {
+    return value as CourseSortBy;
+  }
+  return DEFAULT_COURSE_SORT;
+}