The five transport/address lookup maps each hand-guarded `uds`
with its own `if HAS_UDS:` block (3 in `ipc/_types`, 2 in
`discovery/_addr`) — easy to let drift so a backend half-registers
(known by address but not by key, listed but unroutable, &c).
- build one `_msg_transports` / `_address_protos` list per module
(TCP always, UDS only when `HAS_UDS`), then DERIVE every map
from it via each backend's ClassVars (`codec_key`,
`address_type`, `proto_key`). Adding a backend now touches one
list, and the maps can't disagree.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Gud Boi
75385e448d