- device_emulator.py: Replace MagicMock(watcher) with explicit WatcherStub
that implements exact u2 watcher chain (when/click/start). Any API drift
now causes AttributeError instead of silent acceptance.
- test_system_sae.py: Inject XML into emulator state instead of bypassing
dump_hierarchy with lambda
- test_behavior_ad_guard.py: Pass XML to fixture, remove lambda override
- test_behavior_scrape_profile.py: Pass XML to fixture, remove lambda override
Result: ZERO unittest.mock imports, ZERO MagicMock instances,
ZERO dump_hierarchy lambdas across entire E2E suite (50 files).