Split the Emission Cadence promotion gate and promote to candidate (T06)

The gate required two independent source implementations before draft
promotion, which made one sentence do two jobs: whether the contract is
specified well enough to implement against, which this repository can answer,
and whether it survives implementers who did not write it, which it cannot. The
second blocked the first, so the standard sat at draft — a word that reads as
unfinished specification — when what was missing was adoption.

Candidate now requires schema coverage of every form, one-command validation of
an arbitrary source-owned declaration, a content-addressed bundle a source can
pin to, separation of declaration from observation, and a documented external
consumption path. All are met and were re-tested rather than assumed. Stable
requires two source-owned declarations from independent owners pinned to a
digest, an observer result from a third party, and a recorded incompatibility or
a recorded absence of one — stricter than the sentence it replaces.

Emission Cadence moves to candidate at document version 0.2.0. The wire contract
is untouched at schema version 0.1, and no field, form or validation rule
changes, so a producer conformant yesterday is conformant today.

What was given up: candidate carries no interoperability evidence at all. The
standard states that in its own section 10, naming that no consumer has
implemented the contract and that its worked example is not a source-owned
declaration. The gate now lives in the standard rather than only in SCOPE.md, so
a reader meets it where the contract is.

Recorded as INFO-DEC-2026-002 with the reasoning in history/. INFO-WP-0019
closes: all six tasks done.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 3588@bnt-lap001
Assistant-Session: 24b80f66-e5a7-4e61-99fe-2d422e6d17da

history/2026-09-21_000846+0200-emission-cadence-promotion-gate.md

@@ -0,0 +1,69 @@
+# Emission Cadence promotion gate — restatement
+
+Date: 2026-09-21 (Europe/Berlin)
+Decision: **INFO-DEC-2026-002 — split the gate; promote to candidate.**
+Origin: INFO-WP-0019-T06, waiting since 2026-09-05, rechecked 2026-09-09 and
+2026-09-20 with no change in the evidence. Operator chose restatement over
+soliciting declarations.
+
+## The problem with the gate as written
+
+SCOPE.md required "two independent Emission Cadence source implementations"
+before draft promotion. One sentence was doing two different jobs:
+
+1. **Is the contract specified well enough to implement against?** A question
+   about this repository's own work, answerable here.
+2. **Does the contract survive contact with implementers who did not write it?**
+   A question about other people's systems, unanswerable here by construction.
+
+Because both sat behind one gate, the second blocked the first. The standard
+stayed at `draft` — a word that reads as "unfinished specification" — when what
+was actually missing was adoption. A reader could not tell which.
+
+The canon-side work has been complete since 2026-09-05 and was re-tested on
+2026-09-20: `emission-review` validates an arbitrary source-owned declaration
+against the named schema and reports `operational_truth_assessed: false`;
+`export-emission-contract` produces a content-addressed bundle at digest
+`972c0b6701d1693f` whose manifest states the adoption requirement in words; the
+consumption path is documented for a consumer outside this repository. Nothing
+in that set needs an external party.
+
+## Decision
+
+Split the gate into two levels, recorded in the standard itself as section 10
+rather than only in SCOPE.md, so a reader meets it where the contract is.
+
+- **Candidate** — the contract is specified, machine-checkable, and stable
+  enough to implement against. Met today. Asserts nothing about adoption.
+- **Stable** — the contract survives independent implementation: two
+  source-owned declarations from owners independent of each other and of this
+  repository, pinned to a contract digest, plus an observer result from a party
+  other than the declaring source, and a recorded incompatibility or recorded
+  absence of one.
+
+Emission Cadence moves to `candidate` at document version `0.2.0`. The wire
+contract is unchanged at schema version `0.1`, and `0.x` still means
+incompatible change remains possible with migration guidance.
+
+## What was given up
+
+The original gate, honestly read, meant the standard could not be promoted at
+all until two external owners acted. Splitting it means this repository can now
+say the specification work is finished while adoption is not — but it also means
+**the word "candidate" no longer carries any interoperability evidence**. That
+is a real reduction in what a status word tells a reader, and it is mitigated
+only by the standard stating plainly, in section 10, that no consumer has
+implemented the contract and that its own worked example is not a source-owned
+declaration.
+
+The stable gate is deliberately *stricter* than what it replaced: it adds the
+observer result and the recorded-incompatibility requirement, which the single
+sentence never asked for. Nothing was relaxed about interoperability; what
+changed is that the claim is now made at the level where it can be earned.
+
+## Limits
+
+Agent review, not human sign-off. Candidate status records no consumer adoption,
+no runtime claim, and no conformance statement by any party. The promotion
+changes no field, form or validation rule; a producer conformant yesterday is
+conformant today.