test: update smoke and regression suites for dual-renderer paths

Offscreen harnesses now resize+show before load, use per-instance webengine profile dirs and explicit exit codes; compaction and bash stream suites follow the renamed internals.

tests/smoke_timeline.py

@@ -14,6 +14,10 @@ os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
 os.environ.setdefault("HAOCODE_RENDER", "software")
 os.environ["QTWEBENGINE_CHROMIUM_FLAGS"] = "--disable-gpu"  # 绕过 AMD 核显 context lost
 
+# 铁律（P0-01）：临时数据库 + 临时配置必须在 import MainWindow 之前完成
+from tests._test_env import isolate  # noqa: E402
+_TMP = isolate("timeline")  # noqa: E402
+
 from PyQt6.QtWidgets import QApplication  # noqa: E402
 from PyQt6.QtCore import QTimer  # noqa: E402
 from ui.views.main_window import MainWindow  # noqa: E402  (QtWebEngine 已先导入)