feat(dashboard): show admin hints and add the hints admin page

src/utils/hints.js

@@ -0,0 +1,33 @@
+import {apiFetch} from './api.js';
+
+const AUTH = () => import.meta.env.VITE_API_URL;
+
+/**
+ * GET /api/hints: {results: [{id, textEn, textDe, kind, startsAt, endsAt}]}, the running hints the user has not
+ * closed for good, newest first.
+ */
+export const fetchHints = () => apiFetch(`${AUTH()}/api/hints`);
+
+/**
+ * The hint never comes back for this user.
+ */
+export const markHintDone = (hintId) => apiFetch(`${AUTH()}/api/hints/${hintId}/done`, {method: 'PUT'});
+
+/**
+ * PLATFORM_ADMIN only (403 otherwise): {results: [...]}, every hint with doneCount, newest first.
+ */
+export const fetchAdminHints = () => apiFetch(`${AUTH()}/api/admin/hints`);
+
+/**
+ * 201 {id}, or 400 (code INVALID_HINT when the end is not after the start or not in the future).
+ */
+export const createHint = (hint) =>
+    apiFetch(`${AUTH()}/api/admin/hints`, {
+        method: 'POST',
+        headers: {'Content-Type': 'application/json'},
+        body: JSON.stringify(hint),
+    });
+
+export const endHint = (hintId) => apiFetch(`${AUTH()}/api/admin/hints/${hintId}/end`, {method: 'PUT'});
+
+export const hintText = (hint, language) => (language?.startsWith('de') && hint.textDe ? hint.textDe : hint.textEn);