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_email_reader_handoff.py

@@ -0,0 +1,23 @@
+import pytest
+
+from src.clean_agent_preview import email_reader_event
+
+
+RESULT = {'stdout': '**Subject:** Weekly roundup\n**UID:** 162\n**Account:** Inbox (alex@example.com)\n'}
+
+
+@pytest.mark.parametrize('prompt', ['open the weekly email', 'please open it', 'can you view that email'])
+def test_explicit_open_uses_successful_read_identity(prompt):
+    assert email_reader_event(prompt, 'mcp__email__read_email', {'folder': 'Archive'}, RESULT) == {
+        'type': 'email_open', 'uid': '162', 'folder': 'Archive', 'account': 'alex@example.com'}
+
+
+@pytest.mark.parametrize('prompt', ['summarize this email', 'read the weekly email', 'do not open it'])
+def test_normal_read_does_not_open_reader(prompt):
+    assert email_reader_event(prompt, 'read_email', {}, RESULT) is None
+
+
+def test_failed_or_unidentified_message_never_opens():
+    assert email_reader_event('open it', 'read_email', {}, RESULT, failed=True) is None
+    assert email_reader_event('open it', 'list_emails', {}, RESULT) is None
+    assert email_reader_event('open it', 'read_email', {'uid': '162'}, {'stdout': 'Not found'}) is None