Graduate research 058 into design 47's release 4: a check runs only what changed, its tests by the language's build module, its composition by the assigner, in one status

The check took 3 to 4.5 minutes on every change and paid the whole suite again on every re-ask; the operator's target leaves it about a minute. ADRs 0444 to 0447 decide how; the glossary gains composition check and kept verdict, and merge gate is struck once release 4 is delivered (issue 1303).

00-META/glossary.md

@@ -403,14 +403,23 @@ and the operator act. **Recorded by** the controller's `identity` and `licences`
 back when it fails. The domain is continuous integration and delivery, named **delivery**, and its parts live in
 the repository `mesh-delivery` (ADR 0429 §2). **Recorded by** the `mesh-delivery` module (deliveries) and the
 controller (the planner, the rollout) until release 6 of ADR 0429; from each release on, by the parts it builds. **Downstream of** Module, Core, Health and repair and Data.
-**Decided by** ADR 0162, 0218, 0236, 0237, 0238, 0239, 0250, 0267, 0270, 0276, 0323, 0401–0408, 0428, 0429.
+**Decided by** ADR 0162, 0218, 0236, 0237, 0238, 0239, 0250, 0267, 0270, 0276, 0323, 0401–0408, 0428, 0429, 0444–0447.
 **Uses:** module, node, declaration and send (Placement), health (Health and repair), person.
 
-- **merge check** — the two statuses a pull request carries before it may merge: the **merge gate**
-  (`mesh/merge-gate`, the build seat's composed check of the modules the change touches) and the
-  **repository check** (`mesh/repo-check`, the repository's own `merge-check.sh`)
-  (ADR 0238). Both judge the merge of the pull request's head into a named **trunk commit**, made in the
-  build seat's own clone and never pushed (ADR 0323).
+- **merge check** — what a pull request carries before it may merge, judging the merge of its head into a
+  named **trunk commit**, made in the builder's own clone and never pushed (ADR 0323). Until release 4 of
+  ADR 0429 is delivered, two statuses: the **merge gate** (`mesh/merge-gate`, the build seat's composed check of
+  the modules the change touches) and the **repository check** (`mesh/repo-check`, the repository's own
+  `merge-check.sh`) (ADR 0238). From that release, one status, `mesh/check`, written by the checker: the
+  change's tests, run by the language's build module, and the **composition check**; for a delivery group, one
+  verdict on every member's head (ADR 0445, ADR 0447).
+- **composition check** — whether the machines a change touches still compose with it, run by the assigner
+  from the modules the indexer and the builder hold, with the composition the controller sends with
+  (ADR 0446). It replaces the merge gate from release 4 of ADR 0429; the old word is struck once that release
+  is delivered and every design that still says it is reworded (issue 1303).
+- **kept verdict** — a package's passing verdict at one test level, kept by the checker under the digest of
+  everything its tests read, written once and read-only; a check takes it instead of running an unchanged
+  package (ADR 0444).
 - **trunk commit** — the commit of the trunk a merge check's verdict was judged against: the trunk's head when
   the build seat cloned it. The verdict holds for that commit only, and goes out of date when the trunk moves
   (ADR 0323).
@@ -852,7 +861,7 @@ renaming one sense, the old sense moves to a *Not:* line and becomes mechanical.
 | | taking a consumer off a licence | **unbind** (verb `release`, to rename) | Identity and access |
 | | a copy of a work an engine can fetch | **media release** | Media |
 | gate | the judgement on a delivery's first node | **first-node gate** | Delivery |
-| | the pull request status | **merge gate** | Delivery |
+| | the pull request status, until release 4 of ADR 0429 | **merge gate**; from release 4, **composition check** | Delivery |
 | | the part that merges a group and moves the source revision | **gate part** (`mesh-delivery-gate`) | Delivery |
 | | a failed step stopping its module's later steps (ADR 0136) | *a failed step holds its module* | Placement |
 | tier | a level of the mesh | **layer** | Core |
@@ -875,7 +884,8 @@ renaming one sense, the old sense moves to a *Not:* line and becomes mechanical.
 | | the operator's terminal command, `mesh-cli` | **the `nox` command** | Operator and conversation |
 | knowledge base | the module holding the decision records and research efforts whole | **knowledge base** | The record |
 | | the predecessor's operational memory, in older playbooks (issue 430) | none: it no longer exists | — |
-| check | a pull request's two statuses | **merge check**, **merge gate**, **repository check** | Delivery |
+| check | a pull request's two statuses, one from release 4 of ADR 0429 | **merge check**, **merge gate**, **repository check**; from release 4, `mesh/check` | Delivery |
+| | whether the machines a change touches still compose, the assigner's | **composition check** | Delivery |
 | | a delivery group's verdict | **composed check** | Delivery |
 | | the controller's own examination | **self-check** | Health and repair |
 | | a file in `00-META/checks/` | **hq check** | The record |