Studio: align and even out sidebar hover pills

The Recents chat rows started further left than the nav items above them
and the hover pill widths varied. Give every nav and chat group the same
pl-1.5 pr-2 so the pills line up and share one width, and on hover the
chat rows only reserve room for the kebab so the title keeps one more
character.

studio/frontend/src/components/app-sidebar.tsx

@@ -672,11 +672,12 @@ export function AppSidebar() {
       // Recents label text at 16px.
       variant === "project" ? "pl-[39px]" : "pl-3",
       variant === "project"
-        ? "group-hover/project-chat-item:pr-8 group-has-[.sidebar-row-action[data-state=open]]/project-chat-item:pr-8"
+        ? "group-hover/project-chat-item:pr-6 group-has-[.sidebar-row-action[data-state=open]]/project-chat-item:pr-6"
         : isPinned
           ? // Pinned rows show an extra unpin button on hover, so reserve more room.
-            "group-hover/recent-item:pr-16 group-has-[.sidebar-row-action[data-state=open]]/recent-item:pr-8"
-          : "group-hover/recent-item:pr-8 group-has-[.sidebar-row-action[data-state=open]]/recent-item:pr-8",
+            "group-hover/recent-item:pr-16 group-has-[.sidebar-row-action[data-state=open]]/recent-item:pr-6"
+          : // Hover room for the kebab only; title keeps one more character.
+            "group-hover/recent-item:pr-6 group-has-[.sidebar-row-action[data-state=open]]/recent-item:pr-6",
     );
 
     const isRenamingThis =
@@ -962,7 +963,8 @@ export function AppSidebar() {
         )}
       </SidebarHeader>
 
-      <SidebarGroup className="group-data-[collapsible=icon]:px-0 px-1.5 pt-[9px] pb-px shrink-0">
+      {/* Uniform pl-1.5 pr-2 keeps every hover pill the same width, inset from the edge. */}
+      <SidebarGroup className="group-data-[collapsible=icon]:px-0 pl-1.5 pr-2 pt-[9px] pb-px shrink-0">
         <SidebarGroupContent>
           <SidebarMenu>
             <NavItem
@@ -1002,7 +1004,7 @@ export function AppSidebar() {
           scrolled && "is-scrolled",
         )}
       >
-        <SidebarGroup className="group-data-[collapsible=icon]:px-0 px-1.5 py-0 shrink-0">
+        <SidebarGroup className="group-data-[collapsible=icon]:px-0 pl-1.5 pr-2 py-0 shrink-0">
           <SidebarGroupContent>
             <SidebarMenu>
               <NavItem
@@ -1074,7 +1076,7 @@ export function AppSidebar() {
               </CollapsibleTrigger>
             </SidebarGroupLabel>
             <CollapsibleContent>
-              <SidebarGroupContent className="px-1.5">
+              <SidebarGroupContent className="pl-1.5 pr-2">
                 <SidebarMenu>
                   <NavItem
                     icon={TestTubeOutlineIcon}
@@ -1124,7 +1126,7 @@ export function AppSidebar() {
                 </CollapsibleTrigger>
               </SidebarGroupLabel>
               <CollapsibleContent>
-                <SidebarGroupContent className="pl-1 pr-1.5">
+                <SidebarGroupContent className="pl-1.5 pr-2">
                   <SidebarMenu>
                     {pinnedChatItems.map((item) =>
                       renderChatSidebarItem(item, "recent"),
@@ -1146,7 +1148,7 @@ export function AppSidebar() {
                 </CollapsibleTrigger>
               </SidebarGroupLabel>
               <CollapsibleContent>
-                <SidebarGroupContent className="pl-1 pr-1.5">
+                <SidebarGroupContent className="pl-1.5 pr-2">
                   <SidebarMenu>
                     {recentChatItems.map((item) =>
                       renderChatSidebarItem(item, "recent"),