Replace the unshipped `BindspaceIdentity` and `BindspaceHandle` names
with `BindspaceRef` and `Bindspace` across existing lifecycle APIs.
Deats,
- define refs as wire-safe, host-local and non-owning records
- reserve `Bindspace` for the live FD-backed capability
- rename the capability's realized-resource field to `.ref`
- update lifecycle tests and active design contracts
- omit compatibility aliases for the unshipped model names
Prompt-IO: ai/prompt-io/opencode/20260827T211115Z_d130431c_prompt_io.md
(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))
Gud Boi