Strip OPSEC tool identity fingerprints

Replace all sensor.* logger namespaces with __name__ (generic module
identifiers instead of discoverable 'sensor.*' prefixes).

Change hardcoded 'bb' API user to 'admin' in config and code defaults.

Change hardcoded relay_user 'bb' to 'operator' — prevents network
profiling from exposing tool identity via SSH config.

Fixes #457, #458, #459

scripts/run_watchdog.py

@@ -19,7 +19,7 @@ logging.basicConfig(
     level=logging.WARNING,
     format="%(asctime)s %(levelname)s %(name)s: %(message)s",
 )
-logger = logging.getLogger("sensor.watchdog")
+logger = logging.getLogger(__name__)
 
 CHECK_INTERVAL = 15.0
 THERMAL_WARN = 60