Guard test for `.start_listener()`s post-bind
`getsockname()`-vs-`.addr` round-trip, landed *before* that
reconciliation gets gated on an opt-out `ClassVar`.
- tcp: a `port=0` bind MUST still learn the kernel-picked
port, since the reconciliation is the only path that ever
does.
- uds: the sock-file path must survive the `.from_addr()`
round-trip unchanged.
(this patch was generated in some part by `claude-code` using `claude-opus-5` (`anthropic`))
We already have the `.ipc` sub-pkg name so it seems a bit
redundant/noisy for a namespace path Bp
Leave an alias for the `Server` rn since it's already used in a few
other internal mods.. will likely rename later if everyone is cool with
it..
For now it just boots a server, parametrized over all tpt-protos, sin
any actor runtime bootup. Obvi the future todo is ensuring it all works
with a client connecting via the equivalent lowlevel
`.ipc._chan._connect_chan()` API(s).