fix: render TUI pickers as overlays

src/tui/tui-overlays.test.ts

@@ -0,0 +1,60 @@
+import type { Component } from "@mariozechner/pi-tui";
+import { describe, expect, it, vi } from "vitest";
+
+import { createOverlayHandlers } from "./tui-overlays.js";
+
+class DummyComponent implements Component {
+  render() {
+    return ["dummy"];
+  }
+
+  invalidate() {}
+}
+
+describe("createOverlayHandlers", () => {
+  it("routes overlays through the TUI overlay stack", () => {
+    const showOverlay = vi.fn();
+    const hideOverlay = vi.fn();
+    const setFocus = vi.fn();
+    let open = false;
+
+    const host = {
+      showOverlay: (component: Component) => {
+        open = true;
+        showOverlay(component);
+      },
+      hideOverlay: () => {
+        open = false;
+        hideOverlay();
+      },
+      hasOverlay: () => open,
+      setFocus,
+    };
+
+    const { openOverlay, closeOverlay } = createOverlayHandlers(host, new DummyComponent());
+    const overlay = new DummyComponent();
+
+    openOverlay(overlay);
+    expect(showOverlay).toHaveBeenCalledWith(overlay);
+
+    closeOverlay();
+    expect(hideOverlay).toHaveBeenCalledTimes(1);
+    expect(setFocus).not.toHaveBeenCalled();
+  });
+
+  it("restores focus when closing without an overlay", () => {
+    const setFocus = vi.fn();
+    const host = {
+      showOverlay: vi.fn(),
+      hideOverlay: vi.fn(),
+      hasOverlay: () => false,
+      setFocus,
+    };
+    const fallback = new DummyComponent();
+
+    const { closeOverlay } = createOverlayHandlers(host, fallback);
+    closeOverlay();
+
+    expect(setFocus).toHaveBeenCalledWith(fallback);
+  });
+});