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_kimi_thinking_toggle.py

@@ -0,0 +1,17 @@
+import pytest
+
+from src.model_profiles import supports_user_thinking_toggle
+from src.llm_core import _apply_hosted_thinking_mode
+
+
+@pytest.mark.parametrize('model', ['kimi-k3', 'moonshotai/kimi-k3', 'kimi-k2.5', 'kimi-k2.6'])
+@pytest.mark.parametrize('mode', ['on', 'off'])
+def test_kimi_toggle_matches_hosted_request(model, mode):
+    assert supports_user_thinking_toggle(model)
+    payload = {}
+    _apply_hosted_thinking_mode(payload, 'moonshot', model, mode)
+    assert payload['thinking']['type'] == ('enabled' if mode == 'on' else 'disabled')
+
+
+def test_older_kimi_is_not_assumed_switchable():
+    assert not supports_user_thinking_toggle('kimi-k2-thinking')