Proto foundation + gateway-side of the size/backpressure pass:
- IPC-02: add GatewayHello.max_frame_bytes (regen Generated/); gateway sends
its negotiated worker-frame max in the handshake so the worker can adopt it
instead of a hard-coded default. Worker read-half lands separately.
- IPC-03: give the pipe frame max envelope-overhead headroom above the public
gRPC cap (WorkerFrameProtocolOptions.EnvelopeOverheadReserveBytes = 64 KiB;
default Worker.MaxMessageBytes bumped to 16 MiB + reserve), cross-validate the
headroom at startup, and pre-check command envelope size in WorkerClient so an
oversized command fails only that correlation (ResourceExhausted) instead of
faulting the whole session.
- IPC-04: reject DrainEvents max_events above a public ceiling in the request
validator (worker per-reply cap lands with the worker half).
Docs: GatewayConfiguration, WorkerFrameProtocol, gateway.md.
Tests: headroom validation, DrainEvents bound, oversized-command per-command
failure (pipe-harness, verified on windev).
Joseph Doherty
c8b3a2281a