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swung0x48andClaude Opus 5 0bbe41c291 [MG_Remote] (P6/c6): the normative contract, and the data-plane seam declared but not wired
c6 is P6's contract package. It lands CONTRACT-P6.md plus two headers and
changes nothing: no caller moves, no byte moves on any wire.

THE CONTRACT supersedes P6-CONTRACT-DRAFT.md, which was written before its own
audit and is wrong in four places - the ABI row, "the latch is implemented
unchanged", "cp is transport only", and "a transport swap and nothing else".
a6 measured all four. It carries 21 rulings, of which the load-bearing one is
D1: the spawned child keeps Transport == Spawn and anti-recursion becomes a
separate Dial axis. ARCHITECTURE.md:488's literal instruction is amended,
because 226 live lines test `Transport != Monolith` to select the SERVER arm
and forcing Monolith flips 148 MG_Backend lines to frontend glue in the one
process that has no frontend.

That ruling can be stated normatively without changing behaviour because of
something a6 found and the contract exploits: TransportMode::Spawn is
UNREACHABLE at this head. ConfigLoader.cpp:344 is the only writer for the
string "spawn" and it writes Monolith. So every rule conditioned on
Transport == Spawn constrains a state no process can enter - and the same fact
is why ConfigLoader's named refusal cannot currently falsify itself, which is
sm's to fix and §9.5's arm-proof gate to catch.

THE SEAM. ITransport says in its own header that the hot path bypasses it;
below it there was no interface of any kind, because Ring.h, ReplySlot.h and
EventRing.h each take a raw void* plus a capacity. ILink.h is that missing
thing. It is setup-time, not hot-path: no method is called per record or inside
a spin predicate, because Doorbell::Wait's predicate runs 1e5-1e6 times a frame
reading watermarks straight off the page, and because the only lane that could
measure a virtual there has four times the dispersion of the effect - a gate
that can only print "within noise" is ID-124 one level down.

StreamLink.h is declared and implemented by nobody, and that is its job: ILink's
adequacy is a claim only a compile can settle. Writing it forced three methods
the brief did not name - ResolveSpan, FlushProgress, and the reply pair - so it
has already earned its keep. Delete one ILink method it declares and the build
goes red.

Deliberately NOT here, each for a reason the contract records: Watermark::Reached
is not redefined (SessionRings.h owns it); Ring.cpp's reserve/pop bodies are not
relocated into a header that would then need the logger; RingControl is not
regrouped, because that rename is 109 production sites with five behind a
non-Android #if, so it is lk's with a published itemisation; and the schema rows
are specified but left to hs, because deprecating SurfaceReply.defaultFb while
appending `result` changes CreateSurfaceReply's arity and the existing
six-argument call would silently bind its defaultFb 0 to result.

INERTNESS IS STRUCTURAL, not measured. Zero object dependency files reference
either header, zero build rules do, and nothing in the tree includes them.
Verified anyway on both flavours: pull and split each have 0 symbols added,
0 removed, and .text byte-identical (10822147 / 11681395). check_doc_citations
resolves all 61 citations.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-21 08:35:50 -04:00
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