test(4-files): repair 4 failing test suites

FeedbackModal (5 fails): FileDropzone migrated the file input behind a
role=button wrapper div; the hidden input had no accessible label, so
getByLabelText finds the outer div not the input. Move aria-label from
the outer div onto the input so fireEvent.change reaches the onChange
handler. Thumbnails render correctly once the input is findable.

purchases-page.misc-filter (1 fail): showApprovalFilter = useIsLabMode()
=== true, but useIsLabMode was not mocked, so the Awaiting-approval chip
was filtered out before render. Add useIsLabMode mock returning true --
the suite tests a member in a lab-mode folder, which is the only context
where the chip is visible.

WorkbenchExperimentsPanel.sharedFilter (1 fail): data-tour-target was
stamped on the board-view card wrapper but not on the list-view row.
Default view is list, so the section-6.16 cursor-demo anchors were absent.
Mirror the labTourTarget logic onto the list row so the cursor demo can
find the anchors regardless of view mode.

InlineMarkdownEditor.loro: already passing (5/5) -- no changes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: gnick18

frontend/src/app/__tests__/purchases-page.misc-filter.test.tsx

@@ -92,6 +92,13 @@ vi.mock("@/hooks/useAccountType", () => ({
   useAccountType: () => "member",
 }));
 
+// The awaiting-approval chip renders only in lab mode (showApprovalFilter =
+// useIsLabMode() === true). This suite tests the chip in a lab-mode context
+// where a member is waiting on the lab head for approval.
+vi.mock("@/hooks/useIsLabMode", () => ({
+  useIsLabMode: () => true,
+}));
+
 // Purchases UX fix Bug 3 (2026-05-24): the new banner CTA uses
 // `useRouter().push("/lab-overview")`. The misc-filter suite never
 // triggers it (account_type is "member"), but the hook still has to

frontend/src/components/ui/FileDropzone.tsx

@@ -107,7 +107,6 @@ export default function FileDropzone({
     <div
       role="button"
       tabIndex={disabled ? -1 : 0}
-      aria-label={ariaLabel}
       aria-disabled={disabled || undefined}
       // This surface handles the file itself, so opt out of the window-level
       // GlobalDropGuard: data-attach-target suppresses its "not supported" toast,
@@ -179,6 +178,7 @@ export default function FileDropzone({
         accept={accept}
         multiple={multiple}
         disabled={disabled}
+        aria-label={ariaLabel}
         className="hidden"
         onChange={(e) => {
           emit(e.target.files);

frontend/src/components/workbench/WorkbenchExperimentsPanel.tsx

@@ -839,6 +839,15 @@ export default function WorkbenchExperimentsPanel({
         key={taskKey(t)}
         data-beaker-target={`experiment:${taskKey(t)}`}
         data-testid="experiment-row"
+        data-tour-target={
+          t.is_shared_with_me && t.owner === BEAKERBOT_LAB_USERNAME
+            ? t.shared_permission === "edit"
+              ? "workbench-shared-edit-experiment"
+              : t.shared_permission === "view"
+                ? "workbench-shared-view-experiment"
+                : undefined
+            : undefined
+        }
         onClick={() => setSelectedTask(t)}
         onContextMenu={(e) => {
           e.preventDefault();