VerseVDI-Protocol/openspec/changes/gateway-terminal-receipt/proposal.md

Why

A public independent QUIC regression proved that closing the gateway connection immediately after writing the reliable terminal event can discard that event, while waiting for the client to close leaves session ownership with the client. The registered bidirectional control flow needs one bounded receipt semantic so the gateway can close only after observed delivery or a fixed receipt deadline.

What Changes

• Add a client-to-gateway terminal receipt to the existing bounded VGF1 envelope on control.ack.v1.
• Keep the receipt payload empty and valid only while one terminal event is awaiting receipt.
• Preserve the existing IDR, FEC, termination, rumble, and HDR meanings.

Capabilities

New Capabilities

None.

Modified Capabilities

• gateway-input-feedback: Permit the narrowly scoped terminal receipt in the existing reliable control envelope.

Impact

This changes the immutable Protocol semantics consumed by the GPLv3 Data Plane and independent Verse clients. It adds no schema field, dependency, provider address, credential, generic acknowledgement framework, or provider-facing message.