fix(ui): allow manual prompt bar resize (#1201)

tests/test_prompt_bar_manual_resize.py

@@ -0,0 +1,16 @@
+from pathlib import Path
+
+
+CSS = Path("static/style.css").read_text(encoding="utf-8")
+UI_JS = Path("static/js/ui.js").read_text(encoding="utf-8")
+
+
+def test_prompt_bar_exposes_desktop_resize_handle():
+    assert "resize: vertical;" in CSS
+    assert "max-height: min(60vh, 600px);" in CSS
+
+
+def test_auto_resize_preserves_a_manually_chosen_height():
+    assert "textarea._manualResizeHeight = height;" in UI_JS
+    assert "const manualHeight = textarea._manualResizeHeight || 0;" in UI_JS
+    assert "const maxHeight = Math.max(autoMaxHeight, manualHeight);" in UI_JS