[codex] Add Button loading state

src/components/Button.tsx

@@ -1,4 +1,5 @@
 import { type ButtonHTMLAttributes } from "react";
+import { Spinner } from "./Spinner";
 
 type Variant = "primary" | "secondary" | "danger";
 
@@ -23,13 +24,21 @@ export function Button({
   variant = "primary",
   loading = false,
   className = "",
+  disabled,
+  children,
   ...rest
 }: ButtonProps) {
+  const isDisabled = disabled || loading;
+
   return (
     <button
       {...rest}
+      disabled={isDisabled}
       aria-busy={loading || undefined}
-      className={`rounded-full px-5 py-2 text-sm font-medium disabled:opacity-50 disabled:cursor-not-allowed ${variants[variant]} ${ring} ${className}`}
-    />
+      className={`inline-flex items-center justify-center gap-2 rounded-full px-5 py-2 text-sm font-medium disabled:opacity-50 disabled:cursor-not-allowed ${variants[variant]} ${ring} ${className}`}
+    >
+      {loading && <Spinner label="Loading" />}
+      {children}
+    </button>
   );
 }

src/components/__tests__/Button.test.tsx

@@ -0,0 +1,30 @@
+import { render, screen } from "@testing-library/react";
+import { Button } from "../Button";
+
+describe("Button", () => {
+  it("renders children without busy state by default", () => {
+    render(<Button>Save</Button>);
+
+    const button = screen.getByRole("button", { name: "Save" });
+    expect(button).toBeEnabled();
+    expect(button).not.toHaveAttribute("aria-busy");
+    expect(screen.queryByRole("status")).not.toBeInTheDocument();
+  });
+
+  it("disables the button and exposes busy state while loading", () => {
+    render(<Button loading>Save</Button>);
+
+    const button = screen.getByRole("button", { name: /save/i });
+    expect(button).toBeDisabled();
+    expect(button).toHaveAttribute("aria-busy", "true");
+    expect(screen.getByRole("status")).toHaveTextContent("Loading");
+  });
+
+  it("preserves explicit disabled state when not loading", () => {
+    render(<Button disabled>Delete</Button>);
+
+    const button = screen.getByRole("button", { name: "Delete" });
+    expect(button).toBeDisabled();
+    expect(button).not.toHaveAttribute("aria-busy");
+  });
+});