feat: add heats frontend API and HeatsBanner component

- Add divisionsAPI, competitionTypesAPI, heatsAPI to frontend services
- Create HeatsBanner component for declaring competition heats
- Support dynamic heat entry (add/remove heats)
- Validate required fields (competition type, division, heat number)
- Optional role selection (Leader/Follower)
- Real-time API integration with backend

frontend/src/services/api.js

@@ -220,4 +220,48 @@ export const eventsAPI = {
   },
 };
 
+// Divisions API (Phase 1.6)
+export const divisionsAPI = {
+  async getAll() {
+    const data = await fetchAPI('/divisions');
+    return data.data;
+  },
+};
+
+// Competition Types API (Phase 1.6)
+export const competitionTypesAPI = {
+  async getAll() {
+    const data = await fetchAPI('/competition-types');
+    return data.data;
+  },
+};
+
+// Heats API (Phase 1.6)
+export const heatsAPI = {
+  async saveHeats(slug, heats) {
+    const data = await fetchAPI(`/events/${slug}/heats`, {
+      method: 'POST',
+      body: JSON.stringify({ heats }),
+    });
+    return data;
+  },
+
+  async getMyHeats(slug) {
+    const data = await fetchAPI(`/events/${slug}/heats/me`);
+    return data.data;
+  },
+
+  async getAllHeats(slug) {
+    const data = await fetchAPI(`/events/${slug}/heats/all`);
+    return data.data;
+  },
+
+  async deleteHeat(slug, heatId) {
+    const data = await fetchAPI(`/events/${slug}/heats/${heatId}`, {
+      method: 'DELETE',
+    });
+    return data;
+  },
+};
+
 export { ApiError };