a11y(medications): focus-visible ring + 44 px touch floor on intake-history sort headers

Sort headers relied on hover:underline only and dropped below the
44 px touch target floor on mobile. Add focus-visible:ring-* and
min-h-11 sm:min-h-9 so keyboard + touch users can hit the column
header reliably.

src/components/medications/__tests__/intake-history-list-v2.test.tsx

@@ -193,6 +193,29 @@ describe("<IntakeHistoryListV2> — sort indicators", () => {
     expect(html).toContain("arrow-up-down");
   });
 
+  it("applies focus-visible ring + min-h-11 to sort header buttons", () => {
+    const client = makeClient();
+    seedIntake(client, "med-a11y", [
+      {
+        id: "evt-1",
+        medicationId: "med-a11y",
+        scheduledFor: "2026-05-15T08:00:00.000Z",
+        takenAt: "2026-05-15T08:02:00.000Z",
+        skipped: false,
+        source: "WEB",
+        createdAt: "2026-05-15T08:02:00.000Z",
+      },
+    ]);
+    const html = render(
+      <IntakeHistoryListV2 medicationId="med-a11y" />,
+      client,
+    );
+    expect(html).toContain("focus-visible:ring-ring");
+    expect(html).toContain("focus-visible:ring-2");
+    expect(html).toContain("focus-visible:ring-offset-2");
+    expect(html).toContain("min-h-11");
+  });
+
   it("renders pagination controls only when more than one page", () => {
     const client = makeClient();
     // 50 total > pageSize 25 → pagination should render

src/components/medications/intake-history-list-v2.tsx

@@ -188,7 +188,7 @@ export function IntakeHistoryListV2({
                     <button
                       type="button"
                       onClick={() => toggleSort("takenAt")}
-                      className="inline-flex items-center font-medium hover:underline"
+                      className="focus-visible:ring-ring inline-flex min-h-11 items-center rounded-md font-medium hover:underline focus-visible:ring-2 focus-visible:ring-offset-2 focus-visible:outline-none sm:min-h-9"
                       aria-label={t("medications.intakeHistorySortByTaken")}
                     >
                       {t("medications.intakeHistoryColTaken")}
@@ -199,7 +199,7 @@ export function IntakeHistoryListV2({
                     <button
                       type="button"
                       onClick={() => toggleSort("scheduledFor")}
-                      className="inline-flex items-center font-medium hover:underline"
+                      className="focus-visible:ring-ring inline-flex min-h-11 items-center rounded-md font-medium hover:underline focus-visible:ring-2 focus-visible:ring-offset-2 focus-visible:outline-none sm:min-h-9"
                       aria-label={t("medications.intakeHistorySortByScheduled")}
                     >
                       {t("medications.intakeHistoryColScheduled")}