Cap every page at 1920px so layouts stop stretching on ultrawide viewports.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/unit/Layout.test.jsx

@@ -72,6 +72,17 @@ describe("RootLayout", () => {
     expect(container).toBeTruthy();
   });
 
+  test("caps the page shell at 1920px", () => {
+    const tree = RootLayout({ children: <div>Test content</div> });
+    const container = findDescendant(
+      tree,
+      (n) => n.type === "div" && n.props?.className?.includes("min-h-screen"),
+    );
+    expect(container.props.className).toContain("max-w-[1920px]");
+    expect(container.props.className).toContain("mx-auto");
+    expect(container.props.className).toContain("w-full");
+  });
+
   test("renders children directly inside the flex container (no <main> at root)", () => {
     const testContent = "This is test content";
     const tree = RootLayout({ children: <div>{testContent}</div> });