fix(notes): track + remove the select-mode Esc keydown listener so it doesn't leak per open (#2792)

tests/test_notes_select_esc_listener_js.py

@@ -0,0 +1,30 @@
+"""Issue #2791 — the Notes panel's capture-phase "Esc cancels select mode"
+keydown listener must be tracked and removed on close, not leaked anonymously on
+every open/close cycle.
+
+notes.js is a browser ES module with a heavy import chain (can't be node-imported
+in isolation), so — per the repo's convention for DOM-coupled guards (cf. the
+document.js diff-discard and memory.js filter-guard tests) — this asserts the
+tracked-handler pattern in source.
+"""
+from pathlib import Path
+
+SRC = Path("static/js/notes.js").read_text(encoding="utf-8")
+
+
+def test_select_esc_listener_is_tracked_not_anonymous():
+    assert "let _notesSelectEscHandler = null;" in SRC
+    # added via the tracked module-level var in capture phase
+    assert "document.addEventListener('keydown', _notesSelectEscHandler, true);" in SRC
+
+
+def test_select_esc_listener_removed_with_matching_capture_flag():
+    # remove-before-add in openPanel + removal in both close paths => >= 3,
+    # each with the `true` capture flag (a removal without it would not match).
+    removals = SRC.count("document.removeEventListener('keydown', _notesSelectEscHandler, true);")
+    assert removals >= 3, removals
+
+
+def test_old_anonymous_capture_listener_is_gone():
+    # the leak was an inline anonymous capture listener; it must no longer exist.
+    assert "addEventListener('keydown', (e) => {\n    if (e.key === 'Escape' && _selectMode)" not in SRC