Pin the calling task's current netns when `bindspace` is omitted
on Linux/Trio. Retain the scope through child startup so a reused
subprocess worker cannot select a different namespace.
Pass the child-owned FD with its expected device and inode. Check
both before entry, skip `setns()` for an already-current namespace,
and release the transferred FD before runtime setup. Require a
live integer FD for every `Bindspace`.
Add canonical `parent_addr` and `registry_addrs` spawn inputs.
Require an explicit parent to name a live listener and keep each
child's registrar selection in its own `SpawnSpec` and runtime
snapshot, preserving supervisor and sibling inheritance.
Drop async root `bindspace=` entry; retain MP rejection of explicit
bindspaces. Cover real UDS cross-netns bootstrap, stale workers,
concurrent FD borrowers, registrar isolation, and failed starts.
(this patch was generated in some part by `Codex` using `GPT-6`
(`openai`))
Gud Boi
645e25c041