Review feedback from mara ("does the otel info even belong in there?") and
argus: `docs/observability.md` already states twice that the collector's
bridge port is contributed automatically and that neither line is needed for
hyperhive's own telemetry. A second copy of that reasoning in the option
description is a third place to drift from — and drift is what produced the
misleading example this PR started out fixing.
So remove the explanation rather than relocate it. With no otel content in
the option at all there is nothing to keep in sync, and observability.md
stays the one place that owns the otel-specific reasoning.
`example = [ 4318 ]` goes too: 4318 is the OTLP port, so the example still
pointed at otel without naming it.
Also fixes the same confusion one doc over, since it is this PR's subject:
observability.md's own "Network access" section used `otel.endpoint` as the
example for pointing something *else* at a host-local service, immediately
above a warning that you do not need it for otel. It now uses a generic port
and names the reason loopback is wrong from inside a container. While there,
the bridge is `hive-br0`, not `hvbr0` — the only occurrence in the tree.
Refs #3402
fc3bd2a26c