feat: Support incremental mode:

- Support incremental mode in heromodels
- Updated the example to refelct the changes
- Updated the tests to reflect the changes

heromodels/src/models/calendar/calendar.rs

@@ -140,7 +140,11 @@ pub struct Calendar {
 
 impl Calendar {
     /// Creates a new calendar
-    pub fn new(id: u32, name: impl ToString) -> Self {
+    ///
+    /// # Arguments
+    /// * `id` - Optional ID for the calendar. If None, the ID will be auto-generated.
+    /// * `name` - Name of the calendar
+    pub fn new(id: Option<u32>, name: impl ToString) -> Self {
         Self {
             base_data: BaseModelData::new(id),
             name: name.to_string(),