feat: add success toasts for create operations and login

- Add toast.success when workout is created or updated
- Add toast.success when user logs in successfully
- Show descriptive messages with entity names
- Improves user feedback for successful operations

admin-web/components/workout-form.tsx

@@ -213,6 +213,10 @@ export default function WorkoutForm({ initialData, mode = "create" }: WorkoutFor
         }
       }
 
+      toast.success(mode === "edit" ? "Workout updated" : "Workout created", {
+        description: `"${title}" has been ${mode === "edit" ? "updated" : "created"} successfully.`
+      })
+      
       router.push(`/workouts/${result.data.id}`)
     } catch (err) {
       console.error("Failed to save workout:", err)