Iterate on Assistant 2 composer UI (#11306)

- Change project index tool rendering in composer
- Update composer UI style

Release Notes:

- N/A

---------

Co-authored-by: Marshall Bowers <1486634+maxdeviant@users.noreply.github.com>
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

crates/ui/src/components/icon.rs

@@ -87,6 +87,7 @@ pub enum IconName {
     ChevronUp,
     ExpandVertical,
     Close,
+    Code,
     Collab,
     Command,
     Control,
@@ -153,6 +154,7 @@ pub enum IconName {
     Snip,
     Space,
     Split,
+    Spinner,
     Tab,
     Terminal,
     Trash,
@@ -191,6 +193,7 @@ impl IconName {
             IconName::ChevronUp => "icons/chevron_up.svg",
             IconName::ExpandVertical => "icons/expand_vertical.svg",
             IconName::Close => "icons/x.svg",
+            IconName::Code => "icons/code.svg",
             IconName::Collab => "icons/user_group_16.svg",
             IconName::Command => "icons/command.svg",
             IconName::Control => "icons/control.svg",
@@ -257,6 +260,7 @@ impl IconName {
             IconName::Snip => "icons/snip.svg",
             IconName::Space => "icons/space.svg",
             IconName::Split => "icons/split.svg",
+            IconName::Spinner => "icons/spinner.svg",
             IconName::Tab => "icons/tab.svg",
             IconName::Terminal => "icons/terminal.svg",
             IconName::Trash => "icons/trash.svg",