bao's own in-container collector labelled every log line and metric it
forwards `service.name=swarm-bao` (`processors.resource.attributes`,
keyed off `swarm.bao.machine`), while every panel in the shipped
Grafana bao dashboard queries the literal `service.name="bao"` — no
panel has matched since the scrape moved into that collector.
Rename it in the collector instead of templating the dashboard: a new
`collectorServiceName` binding in swarm-bao.nix, deliberately not
`cfg.machine` (that value names the container/receiver, not bao's
display identity), stamps `service.name="bao"` directly. bao.json is
back to its origin/main shape, unchanged.
Adds a module-eval case to checks.module-eval-grafana that reads the
collector's own evaluated config and asserts its service.name matches
every selector the shipped dashboard uses; verified invert-proof by
setting the value back to cfg.machine and confirming that specific
case (and only it) fails.