Judge a pull request's head merged into its trunk, and name the trunk commit

A check judged the head alone, so two pull requests that each passed could
break the trunk together (node-engine #66 on 2026-10-09), and a recheck after
the trunk moved judged the same head again. The build seat now merges the head
into the trunk's head in its own clone, never pushed, fails a head that does not
merge cleanly naming the files, and the verdict names the head, the trunk
commit and the commits read beside it, for the forge and mesh-delivery to weigh
against the trunk's next move (novox/hq ADR 0323, issue 341).

internal/link/build.go

@@ -138,6 +138,9 @@ type GroupMember struct {
 	Repository string   `json:"repository"`
 	Ref        string   `json:"ref"`
 	Paths      []string `json:"paths,omitempty"`
+	// Base is the branch it merges into: the build seat merges the head into that trunk's head before the
+	// group is composed (novox/hq ADR 0323 §6). A build seat from before it composes the head alone.
+	Base string `json:"base,omitempty"`
 }
 
 // Who judges a merge check's gate.
@@ -164,6 +167,14 @@ type CheckOutcome struct {
 	// Gate and RepoCheck are its two layers; Verdict and Summary above are the gate's.
 	Gate      *CheckLayer `json:"gate,omitempty"`
 	RepoCheck *CheckLayer `json:"repo-check,omitempty"`
+	// Head and Trunk are what was judged (novox/hq ADR 0323 §3): the pull request's head merged into the trunk
+	// commit, each as twelve characters. Trunk is empty from a build seat from before it, which judged the head
+	// alone. Beside are the commits of the repositories read beside it, by directory, named and not judged
+	// against (issue 568); Members a delivery group's other heads, each with the trunk commit it merged into.
+	Head    string            `json:"head,omitempty"`
+	Trunk   string            `json:"trunk,omitempty"`
+	Beside  map[string]string `json:"beside,omitempty"`
+	Members []CheckedMember   `json:"members,omitempty"`
 }
 
 // SourceOnSeat names a repository by the seat whose holder serves it and its path there.

internal/link/events.go

@@ -278,14 +278,24 @@ type Checked struct {
 	// status from it — the group's verdict is its owner's, mesh-delivery, to say on each member's head.
 	Group   string          `json:"group,omitempty"`
 	Members []CheckedMember `json:"members,omitempty"`
+	// Trunk is the trunk commit the head was merged into and judged as, twelve characters (novox/hq ADR 0323
+	// §3): the verdict holds for that merge only, and goes out of date when the trunk moves. Empty from a build
+	// seat that judged the head alone. Beside are the commits of the other repositories the check read, by
+	// directory, named and not judged against (issue 568). Took is how long the check ran, for the merge tool
+	// to say how long the next one may take (ADR 0323 §5).
+	Trunk  string            `json:"trunk,omitempty"`
+	Beside map[string]string `json:"beside,omitempty"`
+	Took   string            `json:"took,omitempty"`
 }
 
-// CheckedMember is one head a group's composed check judged.
+// CheckedMember is one head a group's composed check judged, and the trunk commit it was merged into (novox/hq
+// ADR 0323 §6), twelve characters; empty from a build seat that composed the head alone.
 type CheckedMember struct {
 	Owner  string `json:"owner"`
 	Repo   string `json:"repo"`
 	Number int    `json:"number,omitempty"`
 	Commit string `json:"commit"`
+	Trunk  string `json:"trunk,omitempty"`
 }
 
 // ChangePlan is what a change does to the mesh, computed from its diffset — a repository, the branch it
@@ -311,6 +321,9 @@ type ChangePlan struct {
 	Steps []string `json:"steps,omitempty"`
 	// Summary is the plan in one line, for a commit status.
 	Summary string `json:"summary"`
+	// Trunk is the trunk commit the head was merged into when it was judged (novox/hq ADR 0323 §3), twelve
+	// characters: set on the plan a verdict carries, which mesh-delivery keeps with its other inputs.
+	Trunk string `json:"trunk,omitempty"`
 }
 
 // MachinePlan is one machine's part of a change plan.