acp: Add onboarding modal & title bar banner (#36784)

Release Notes:

- N/A

---------

Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>

crates/title_bar/src/onboarding_banner.rs

@@ -119,7 +119,7 @@ impl Render for OnboardingBanner {
                         h_flex()
                             .h_full()
                             .gap_1()
-                            .child(Icon::new(self.details.icon_name).size(IconSize::Small))
+                            .child(Icon::new(self.details.icon_name).size(IconSize::XSmall))
                             .child(
                                 h_flex()
                                     .gap_0p5()

crates/title_bar/src/title_bar.rs

@@ -275,11 +275,11 @@ impl TitleBar {
 
         let banner = cx.new(|cx| {
             OnboardingBanner::new(
-                "Debugger Onboarding",
-                IconName::Debug,
-                "The Debugger",
-                None,
-                zed_actions::debugger::OpenOnboardingModal.boxed_clone(),
+                "ACP Onboarding",
+                IconName::Sparkle,
+                "Bring Your Own Agent",
+                Some("Introducing:".into()),
+                zed_actions::agent::OpenAcpOnboardingModal.boxed_clone(),
                 cx,
             )
         });