The State plane's transport adapter.

One crate sits between the wire and the kernel, and nothing else in the workspace touches a generated State type (INV-24). A Container composes this crate's server glue; a caller uses its clients; both speak only the vocabulary polyc_state defines — commands, receipts, cursors, bounded pages, and typed outcomes.

What lives here

• [wire] maps the kernel's types onto their encoding and back, one explicit conversion per type, every field named.
• [error] carries a typed outcome across the wire as a Connect error detail, so the variant a module refused with is the variant its caller reads — never one inferred from a status code.
• [admission] holds the checks the transport boundary makes before a call reaches a module: version, audience, the caller's proven identity, transport budget, and the listener's own lifecycle. Each is a pure function returning the kernel's typed outcome, so a handler branches on nothing itself. It also names the plane's audience once ([STATE_AUDIENCE]), for both the caller that declares it and the listener that serves it.
• [trace] carries one trace across the hop, so a commit and the decision that caused it land in the same trace tree.
• [journal] is the partition journal's client and server glue — the first authority surface this plane serves.
• [feed] is the durable commit feed's, including the resumable server stream a projector tails a partition through.
• [conformance] serves and dials the conformance kit's synthetic family, the test surface the authenticated shell proves itself against.

What does not live here

Policy. Every decision belongs to polyc_state or to an [admission] function whose whole body is one comparison; a handler that reached its own conclusion would be a State module hiding inside a transport. Durability, too: a receipt is minted by the module that committed, and this crate only carries it (INV-22).

See "Inter-plane protocol and transport", docs/proposals/separated-planes.md.