docs: say what the bao dashboard's log panels show

The classifier asked for the docs to move with the three new panels. bao.md gets
a short 'Watching the store' section, including that a flat zero in the
delivered-lines panel means delivery is broken, not that bao is quiet.

docs/swarm/bao.md

@@ -97,6 +97,16 @@ constrain what a policy says. What bounds it:
 responds while every read times out — the failure looks like a stall, not like
 a store that was never initialised.
 
+## Watching the store
+
+The `hyperhive · openbao` dashboard in Grafana shows seal state, uptime,
+request latency, leases and heap from the store's own metrics. Three more
+panels read its journal: the lines delivered, the `[WARN]` and `[ERROR]` lines
+over time, and the recent ones. A flat zero in **Log lines delivered** while
+the store is up means its logs aren't arriving, not that it's quiet. The
+journal gives these lines no severity, so the panels match on the level the
+store writes into the message.
+
 ## TLS
 
 The store serves TLS, and on a host that deploys it you need do nothing: