refactor: move Project Settings below Tools section in sidebar

- Remove Project Settings from Project section
- Add Project Settings as standalone section below Tools/GitHub
- Use empty label for visual separation without header
- Add horizontal separator line above sections without labels
- Rename to "Project Settings" for clarity
- Keep "Global Settings" at bottom of sidebar

apps/ui/src/components/layout/sidebar/hooks/use-navigation.ts

@@ -168,14 +168,6 @@ export function useNavigation({
       });
     }
 
-    // Add Project Settings to Project section
-    projectItems.push({
-      id: 'project-settings',
-      label: 'Settings',
-      icon: Settings,
-      shortcut: shortcuts.projectSettings,
-    });
-
     const sections: NavSection[] = [
       {
         label: 'Project',
@@ -209,6 +201,19 @@ export function useNavigation({
       });
     }
 
+    // Add Project Settings as a standalone section (no label for visual separation)
+    sections.push({
+      label: '',
+      items: [
+        {
+          id: 'project-settings',
+          label: 'Project Settings',
+          icon: Settings,
+          shortcut: shortcuts.projectSettings,
+        },
+      ],
+    });
+
     return sections;
   }, [
     shortcuts,