fix(e2e): harden card selectors for session resume

Co-Authored-By: Codex <noreply@openai.com>

frontend/src/components/library/TreeGridView.tsx

@@ -34,6 +34,8 @@ export function TreeGridView({
       {trees.map((tree) => (
         <div
           key={tree.id}
+          data-testid="tree-card"
+          data-tree-id={tree.id}
           className="relative bg-card border border-border rounded-2xl p-4 transition-all hover:-translate-y-0.5 hover:border-primary/30 hover:shadow-md sm:p-6"
         >
           <div className="mb-2 flex items-start justify-between gap-2">

frontend/src/components/library/TreeListView.tsx

@@ -33,6 +33,8 @@ export function TreeListView({
       {trees.map((tree) => (
         <div
           key={tree.id}
+          data-testid="tree-card"
+          data-tree-id={tree.id}
           className="flex items-center gap-4 bg-card border border-border rounded-2xl p-4 transition-all hover:border-primary/30 hover:shadow-xs"
         >
           {/* Left: Name and Description */}