Transport connect alone can select a foreign, stalled, or ordinary
actor endpoint as the registry. On macOS UDS this also exercises a
fragile connect-and-bail path before every root election.
Extend `Aid` with backward-compatible probe and registrar capability
fields, require a bounded typed handshake, and classify addresses as
absent, occupied, or confirmed registrars. Reject occupied endpoints
instead of binding over them.
Also,
- close `_connect_chan()` in `finally`
- bypass normal peer tracking for election probes
- preserve legacy registrar handshakes with unknown capability
- cover foreign listeners and idle registrar peer state
Review: PR #480 (goodboy)
https://github.com/goodboy/tractor/pull/480
(this patch was generated in some part by `opencode` using
`gpt-5.6-sol` (`openai`))