feat(web): responsive Fields page (stacks on narrow) (#58)

web/src/fields/fields-page.test.tsx

@@ -0,0 +1,17 @@
+import { expect, test } from "vitest";
+import { screen } from "@testing-library/react";
+
+import { renderApp } from "../test/render";
+import { FieldsPage } from "./fields-page";
+
+test("renders the field list and form in a responsive grid", async () => {
+  const { container } = renderApp(<FieldsPage />);
+
+  // both panes are present (master list + detail form)
+  expect(await screen.findByText(/fields/i)).toBeInTheDocument();
+
+  // responsive: single-column by default, two-column at lg
+  const grid = container.querySelector("div.grid");
+  expect(grid?.className).toContain("grid-cols-1");
+  expect(grid?.className).toContain("lg:grid-cols-[20rem_1fr]");
+});

web/src/fields/fields-page.tsx

@@ -20,8 +20,8 @@ export function FieldsPage() {
   return (
     <div className="flex h-full flex-col">
       <PageTitle className="px-4 pt-4 pb-2">{t("fields.title")}</PageTitle>
-      <div className="grid flex-1 grid-cols-[20rem_1fr] overflow-hidden">
-        <div className="overflow-hidden border-r">
+      <div className="grid flex-1 grid-cols-1 overflow-auto lg:grid-cols-[20rem_1fr] lg:overflow-hidden">
+        <div className="overflow-hidden border-b lg:border-r lg:border-b-0">
           <FieldList selectedKey={selected?.key ?? null} onSelect={setSelected} />
         </div>
         <div className="overflow-hidden">