feat: unify headless execution under the Standalone Host

Expose an optional private same-uid Unix operator adapter and JSONL serve/attach CLI using the production Standalone Profile, store, restore lease and shutdown lifecycle. Remove direct Worker subprocess/discovery/readiness/controller sockets and parent socket callbacks; retain metadata-only peer registration and legacy safety readers.

Validated real Host/client input, events, provenance, disconnect, admitted shutdown and shared production restore/duplicate exclusion; normal standalone/worker/manifest/protocol/client/yoi/tui/server tests, root check, rustdoc, fmt and state-contract audit. Runtime lib: 476 passed, damaged_checkout_does_not_block_restore_but_is_rejected_when_used fails at missing_git diagnostic; unchanged restore logic, not relaxed or retried. Runtime bins/docs pass.

crates/standalone/Cargo.toml

@@ -23,7 +23,7 @@ serde.workspace = true
 serde_json.workspace = true
 session-store.workspace = true
 thiserror.workspace = true
-tokio = { workspace = true, features = ["rt", "sync", "time"] }
+tokio = { workspace = true, features = ["rt", "sync", "time", "net", "io-util", "io-std", "signal"] }
 uuid = { workspace = true, features = ["v7"] }
 worker.workspace = true