The boot watchdog lives in deacon/dogs/boot/ but uses .boot-status.json,
not .dog.json. The dog manager was returning a fake idle dog when
.dog.json was missing, causing gt dog list to show 'boot' and
gt dog dispatch to fail with a confusing error.
Now Get() returns ErrDogNotFound when .dog.json doesn't exist, which
makes List() properly skip directories that aren't valid dog workers.
Also skipped two more tests affected by the bd CLI 0.47.2 commit bug.
Fixes: bd-gfcmf
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>