Standardize agent previews (#29790)

This PR makes agent previews render like any other preview in the
component preview list & pages.

Page:

![CleanShot 2025-05-02 at 09 17
12@2x](https://github.com/user-attachments/assets/8b611380-b686-4fd6-9c76-de27e35b0b38)

List:

![CleanShot 2025-05-02 at 09 17
33@2x](https://github.com/user-attachments/assets/ab063649-dc3c-4c95-969b-c3795b2197f2)


Release Notes:

- N/A

crates/component/src/component.rs

@@ -18,6 +18,9 @@ pub trait Component {
     fn name() -> &'static str {
         std::any::type_name::<Self>()
     }
+    fn id() -> ComponentId {
+        ComponentId(Self::name())
+    }
     /// Returns a name that the component should be sorted by.
     ///
     /// Implement this if the component should be sorted in an alternate order than its name.
@@ -81,7 +84,7 @@ pub fn register_component<T: Component>() {
     let component_data = (T::scope(), T::name(), T::sort_name(), T::description());
     let mut data = COMPONENT_DATA.write();
     data.components.push(component_data);
-    data.previews.insert(T::name(), T::preview);
+    data.previews.insert(T::id().0, T::preview);
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]