feat(desktop): tag each sidebar project row with data-sessions-project

The merged data-attributes only exposed data-sessions-project on the
sessions wrapper once a project was entered, so in the project overview
(and every other mode) the attribute was absent. Put it on each project
overview row too, carrying that row's project id, so a custom skin can
target an individual project from the list — the parallel to the entered
wrapper's attribute.

apps/desktop/src/app/chat/sidebar/projects/overview-row.test.tsx

@@ -86,4 +86,10 @@ describe('ProjectOverviewRow', () => {
 
     expect(onNewSession).toHaveBeenCalledWith(null)
   })
+
+  it('tags the row with data-sessions-project so a skin can target one project', () => {
+    const { container } = render(<ProjectOverviewRow project={project} />)
+
+    expect(container.querySelector('[data-sessions-project="p1"]')).toBeTruthy()
+  })
 })

apps/desktop/src/app/chat/sidebar/projects/overview-row.tsx

@@ -158,7 +158,11 @@ export function ProjectOverviewRow({
   )
 
   return (
-    <div className={cn(dragging && 'relative z-10')} ref={ref} style={style}>
+    // Tag each project sibling with its id so a custom skin can target one
+    // project in the overview — the parallel to the entered-project wrapper's
+    // `data-sessions-project` (index.tsx), which only fires once you've drilled
+    // in. Here it's present on every row of the list.
+    <div className={cn(dragging && 'relative z-10')} data-sessions-project={project.id} ref={ref} style={style}>
       {/* Home has no per-project actions, so it gets no right-click menu. */}
       {project.isNoProject ? (
         shell