Update Agent panel to work with CloudUserStore (#35436)

This PR updates the Agent panel to work with the `CloudUserStore`
instead of the `UserStore`, reducing its reliance on being connected to
Collab to function.

Release Notes:

- N/A

---------

Co-authored-by: Richard Feldman <oss@rtfeldman.com>

crates/zed/src/main.rs

@@ -556,7 +556,12 @@ pub fn main() {
         );
         supermaven::init(app_state.client.clone(), cx);
         language_model::init(app_state.client.clone(), cx);
-        language_models::init(app_state.user_store.clone(), app_state.client.clone(), cx);
+        language_models::init(
+            app_state.user_store.clone(),
+            app_state.cloud_user_store.clone(),
+            app_state.client.clone(),
+            cx,
+        );
         agent_settings::init(cx);
         agent_servers::init(cx);
         web_search::init(cx);

crates/zed/src/zed.rs

@@ -4488,7 +4488,12 @@ mod tests {
             );
             image_viewer::init(cx);
             language_model::init(app_state.client.clone(), cx);
-            language_models::init(app_state.user_store.clone(), app_state.client.clone(), cx);
+            language_models::init(
+                app_state.user_store.clone(),
+                app_state.cloud_user_store.clone(),
+                app_state.client.clone(),
+                cx,
+            );
             web_search::init(cx);
             web_search_providers::init(app_state.client.clone(), cx);
             let prompt_builder = PromptBuilder::load(app_state.fs.clone(), false, cx);

crates/zed/src/zed/component_preview/preview_support/active_thread.rs

@@ -17,9 +17,10 @@ pub fn load_preview_thread_store(
     cx: &mut AsyncApp,
 ) -> Task<Result<Entity<ThreadStore>>> {
     workspace
-        .update(cx, |_, cx| {
+        .update(cx, |workspace, cx| {
             ThreadStore::load(
                 project.clone(),
+                workspace.app_state().cloud_user_store.clone(),
                 cx.new(|_| ToolWorkingSet::default()),
                 None,
                 Arc::new(PromptBuilder::new(None).unwrap()),