agent: Add component preview for Zed AI configuration (#33704)

As we are in the process of improving our Onboarding UX for Zed AI, I
added component previews for the Zed AI Configuration section. This
should make it easier to inspect the different states we can run into.

<img width="1198" alt="image"
src="https://github.com/user-attachments/assets/eb774f27-9091-450d-bfae-c688d533c25e"
/>


Release Notes:

- N/A

crates/agent_ui/src/agent_panel.rs

@@ -2598,7 +2598,7 @@ impl AgentPanel {
                         Some(ConfigurationError::ProviderPendingTermsAcceptance(provider)) => {
                             parent.child(Banner::new().severity(ui::Severity::Warning).child(
                                 h_flex().w_full().children(provider.render_accept_terms(
-                                    LanguageModelProviderTosView::ThreadtEmptyState,
+                                    LanguageModelProviderTosView::ThreadEmptyState,
                                     cx,
                                 )),
                             ))