Standardize create-flow option steps on one question-and-options layout and Selection sizes.

Method cards, chips, and the right rail now share the two-column shell; last options clear the footer fade, See all stays under the stack, and the left heading no longer jumps when the list expands.

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

tests/unit/Selection.test.jsx

@@ -54,6 +54,33 @@ describe("Selection Component", () => {
 
     const card = screen.getByRole("button");
     expect(card).toHaveClass("flex-row");
+    expect(card).toHaveAttribute("data-selection-size", "l");
+  });
+
+  it("maps size s to a chip with accessible selected state", () => {
+    render(
+      <Selection
+        label="Open membership"
+        supportText="Anyone can join"
+        size="s"
+        selected
+      />,
+    );
+
+    const chip = screen.getByRole("button", {
+      name: "Open membership: Anyone can join",
+    });
+    expect(chip).toHaveAttribute("aria-pressed", "true");
+    expect(chip).toHaveTextContent("Open membership");
+    expect(screen.queryByText("Anyone can join")).not.toBeInTheDocument();
+  });
+
+  it("uses size m for compact tiles and exposes aria-pressed", () => {
+    render(<Selection {...defaultProps} size="m" selected />);
+
+    const card = screen.getByRole("button");
+    expect(card).toHaveAttribute("data-selection-size", "m");
+    expect(card).toHaveAttribute("aria-pressed", "true");
   });
 
   it("does not render a helper icon by default", () => {