Per-handler boundary tests pin each handler's body in isolation.
Adding engine-boundary tests that pin the REGISTRATION layer:
- every expected action name registered, no drops, no extras
- guarded actions register a guard, unguarded ones don't
- every registered handler is callable
- every guard returns a bool
- all four progress callbacks registered in the right slots
- progress_init / progress_finish / record_history / on_library_scan_completed
are invocable through the engine's stored callable shape (not just
the bare extracted function)
- finish callback respects _manages_own_progress flag at the engine
boundary too
- library_scan_completed wiring registers a callback on the scan
manager and that callback fires engine.emit when invoked
- every handler returns a `{'status': ...}` dict on a minimal config
trigger -- proves no handler raises into the engine, even when its
guard / short-circuit / error path is the one taken
Uses a minimal _RecordingEngine that captures registrations + a
_RecordingScanMgr that captures completion callbacks. No real
AutomationEngine, no real Flask app, no real DB. The kettui standard
for refactor PRs: don't ship "behavior preserved" claim that's only
validated at the function boundary -- exercise the engine seam too.
EXPECTED_ACTION_NAMES + EXPECTED_GUARDED_ACTIONS frozen sets at the
top: any future drift (rename / drop / add a handler / change which
ones are guarded) fails this test immediately so refactor PRs can't
quietly mutate the registration shape.
13 new tests, 164 automation tests pass total.
