v1.37.1 — Fix dependents-cascade crash

Fixed

• Restart-dependents cascade crashed with cannot unpack non-iterable bool object (#2, @famewolf). A group head (e.g. gluetun) updated fine, then kicking its dependents threw — the head showed a second, bogus ❌ line. A stray bot-local _wait_healthy returning a bool shadowed the checker's canonical 3-tuple (outcome, state, health), so outcome, _, _ = self._wait_healthy(...) tried to unpack a bool. The cascade now uses the checker's 3-tuple _wait_healthy; the duplicate bool method is removed. The regression test was masking it (it stubbed a 3-tuple onto the bot) and now stubs the checker, exercising the real path.

Full 19-script regression sweep green.