Preserve preview harness, editor, email and task improvements

Snapshot current maintainer-preview application changes and regression fixtures for integration into lab. Excludes local runtime data, evaluation outputs and source backups. Focused Python regression selection: 140 passed; full suite not certified.

tests/test_tour_hint_dismiss_js.py

@@ -0,0 +1,69 @@
+"""Exercise tutorial dismissal against the real shared Escape stack."""
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+ROOT = Path(__file__).resolve().parents[1]
+pytestmark = pytest.mark.skipif(not shutil.which('node'), reason='node unavailable')
+
+
+def test_tutorial_hints_dismiss_one_at_a_time_and_release_every_close_path():
+    stack = (ROOT / 'static/js/escMenuStack.js').read_text()
+    helper = (ROOT / 'static/js/tourHintDismiss.js').read_text().split('\n', 1)[1]
+    script = stack + '\n' + helper + r'''
+import assert from 'node:assert/strict';
+const timers = new Map();
+let nextTimer = 0;
+globalThis.setTimeout = (fn, delay) => { const id = ++nextTimer; timers.set(id, {fn, delay}); return id; };
+globalThis.clearTimeout = id => timers.delete(id);
+function hint() {
+  const listeners = new Map();
+  const classes = new Set();
+  return {
+    isConnected: true,
+    classList: {add: name => classes.add(name), contains: name => classes.has(name)},
+    querySelector: () => ({
+      addEventListener: (type, fn) => listeners.set(type, fn),
+      removeEventListener: type => listeners.delete(type),
+    }),
+    click: () => listeners.get('click')?.(),
+    remove() { this.isConnected = false; },
+  };
+}
+let windowClosed = 0;
+registerEscapeLayer(() => windowClosed++);
+const first = hint(), second = hint();
+let firstClosed = 0, secondClosed = 0;
+bindTourHintDismiss(first, {timeout: 14000, onDismiss: () => firstClosed++});
+bindTourHintDismiss(second, {timeout: 6500, onDismiss: () => secondClosed++});
+assert.equal(dismissTopEscapeLayer(), true);
+assert.equal(secondClosed, 1);
+assert.equal(firstClosed, 0);
+assert.equal(windowClosed, 0);
+assert.equal(second.classList.contains('tour-hint-out'), true);
+second._dismiss();
+second.click();
+assert.equal(secondClosed, 1);
+assert.equal([...timers.values()].some(t => t.delay === 6500), false);
+first.click();
+assert.equal(firstClosed, 1);
+assert.equal(_openMenuCount(), 1);
+assert.equal([...timers.values()].some(t => t.delay === 14000), false);
+assert.equal(dismissTopEscapeLayer(), true);
+assert.equal(windowClosed, 1);
+const timed = hint();
+let timedClosed = 0;
+bindTourHintDismiss(timed, {timeout: 100, onDismiss: () => timedClosed++});
+[...timers.values()].find(t => t.delay === 100).fn();
+assert.equal(timedClosed, 1);
+assert.equal(dismissTopEscapeLayer(), false);
+const detached = hint();
+bindTourHintDismiss(detached);
+detached.remove();
+assert.equal(dismissTopEscapeLayer(), false);
+'''
+    result = subprocess.run(['node', '--input-type=module'], input=script,
+                            text=True, capture_output=True, timeout=15)
+    assert result.returncode == 0, result.stderr