Code maintainability fixes

src/services/plans.ts

@@ -0,0 +1,18 @@
+import { WorkoutPlan } from '../types';
+import { api } from './api';
+
+export const getPlans = async (userId: string): Promise<WorkoutPlan[]> => {
+    try {
+        return await api.get<WorkoutPlan[]>('/plans');
+    } catch {
+        return [];
+    }
+};
+
+export const savePlan = async (userId: string, plan: WorkoutPlan): Promise<void> => {
+    await api.post('/plans', plan);
+};
+
+export const deletePlan = async (userId: string, id: string): Promise<void> => {
+    await api.delete(`/plans/${id}`);
+};