fix(ui): share one z-order stack across Notes and modals (#3798)

* fix(notes): bring pane above active windows

* fix(notes): align tool window z-order handoff

---------

Co-authored-by: Matyas Fenyves <16389204+uhhgoat@users.noreply.github.com>

tests/test_notes_z_order_js.py

@@ -0,0 +1,139 @@
+"""Node-driven regression coverage for Notes pane z-order selection.
+
+Notes uses a body-level backdrop instead of the shared `.modal` element, so the
+shared tool-window stack helper must account for both Notes and normal modals
+without importing the full browser-heavy modules.
+"""
+
+import json
+import shutil
+import subprocess
+import textwrap
+from pathlib import Path
+
+import pytest
+
+
+ROOT = Path(__file__).resolve().parents[1]
+HELPER = ROOT / "static" / "js" / "toolWindowZOrder.js"
+pytestmark = pytest.mark.skipif(not shutil.which("node"), reason="node binary not on PATH")
+
+
+def _node_eval(source: str):
+    proc = subprocess.run(
+        ["node", "--input-type=module"],
+        input=source,
+        cwd=ROOT,
+        capture_output=True,
+        text=True,
+        timeout=30,
+    )
+    assert proc.returncode == 0, proc.stderr
+    return json.loads(proc.stdout.strip())
+
+
+def test_notes_z_order_uses_floor_when_no_tool_windows_are_open():
+    values = _node_eval(
+        textwrap.dedent(
+            f"""
+            import {{ topToolWindowZ }} from '{HELPER.as_uri()}';
+            const root = {{ querySelectorAll() {{ return []; }} }};
+            console.log(JSON.stringify({{ z: topToolWindowZ({{ root, getStyle: () => ({{}}) }}) }}));
+            """
+        )
+    )
+
+    assert values == {"z": 250}
+
+
+def test_notes_z_order_lands_above_highest_visible_tool_window():
+    values = _node_eval(
+        textwrap.dedent(
+            f"""
+            import {{ topToolWindowZ }} from '{HELPER.as_uri()}';
+            const cls = (...names) => ({{ contains: (name) => names.includes(name) }});
+            const elements = [
+              {{ id: 'memory', classList: cls(), style: {{ zIndex: '320' }} }},
+              {{ id: 'research', classList: cls(), style: {{ zIndex: '415' }} }},
+              {{ id: 'invalid', classList: cls(), style: {{ zIndex: 'auto' }} }},
+            ];
+            const root = {{ querySelectorAll() {{ return elements; }} }};
+            const top = topToolWindowZ({{ root, getStyle: (el) => el.style }});
+            console.log(JSON.stringify({{ top, notes: top + 1 }}));
+            """
+        )
+    )
+
+    assert values == {"top": 415, "notes": 416}
+
+
+def test_modal_z_order_handoff_lands_above_notes_tie_on_first_click():
+    values = _node_eval(
+        textwrap.dedent(
+            f"""
+            import {{ nextToolWindowZ }} from '{HELPER.as_uri()}';
+            const cls = (...names) => ({{ contains: (name) => names.includes(name) }});
+            const modal = {{ id: 'modal', classList: cls(), style: {{ zIndex: '416' }} }};
+            const notes = {{ id: 'notes', classList: cls(), style: {{ zIndex: '416' }} }};
+            const elements = [modal, notes];
+            const root = {{ querySelectorAll() {{ return elements; }} }};
+            const z = nextToolWindowZ({{
+              exclude: modal,
+              current: modal.style.zIndex,
+              root,
+              getStyle: (el) => el.style,
+            }});
+            console.log(JSON.stringify({{ z }}));
+            """
+        )
+    )
+
+    assert values == {"z": 417}
+
+
+def test_modal_z_order_keeps_current_z_when_already_above_stack():
+    values = _node_eval(
+        textwrap.dedent(
+            f"""
+            import {{ nextToolWindowZ }} from '{HELPER.as_uri()}';
+            const cls = (...names) => ({{ contains: (name) => names.includes(name) }});
+            const modal = {{ id: 'modal', classList: cls(), style: {{ zIndex: '420' }} }};
+            const notes = {{ id: 'notes', classList: cls(), style: {{ zIndex: '416' }} }};
+            const root = {{ querySelectorAll() {{ return [modal, notes]; }} }};
+            const z = nextToolWindowZ({{
+              exclude: modal,
+              current: modal.style.zIndex,
+              root,
+              getStyle: (el) => el.style,
+            }});
+            console.log(JSON.stringify({{ z }}));
+            """
+        )
+    )
+
+    assert values == {"z": 420}
+
+
+def test_notes_z_order_ignores_hidden_minimized_and_excluded_windows():
+    values = _node_eval(
+        textwrap.dedent(
+            f"""
+            import {{ topToolWindowZ }} from '{HELPER.as_uri()}';
+            const cls = (...names) => ({{ contains: (name) => names.includes(name) }});
+            const excluded = {{ id: 'notes', classList: cls(), style: {{ zIndex: '900' }} }};
+            const elements = [
+              excluded,
+              {{ id: 'hidden-class', classList: cls('hidden'), style: {{ zIndex: '800' }} }},
+              {{ id: 'minimized', classList: cls('modal-minimized'), style: {{ zIndex: '700' }} }},
+              {{ id: 'display-none', classList: cls(), style: {{ zIndex: '600', display: 'none' }} }},
+              {{ id: 'visibility-hidden', classList: cls(), style: {{ zIndex: '500', visibility: 'hidden' }} }},
+              {{ id: 'visible', classList: cls(), style: {{ zIndex: '310' }} }},
+            ];
+            const root = {{ querySelectorAll() {{ return elements; }} }};
+            const top = topToolWindowZ({{ exclude: excluded, root, getStyle: (el) => el.style }});
+            console.log(JSON.stringify({{ top }}));
+            """
+        )
+    )
+
+    assert values == {"top": 310}