J3 pick for A3p: delivery.VersionNumbered and BuildAnswer.OutOfStep as join-mesh-sdk 712b21b has them

Only version_numbered.go and stepasks.go of 712b21b, so mesh-build-go builds against them
before the join; identical to the join's, dropped there.

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

go/delivery/stepasks.go

@@ -583,6 +583,10 @@ type BuildAnswer struct {
 	// once (novox/hq ADR 0593 §2): a Go build module reports them, the builder carries them onto the build's end
 	// (BuildLogEntry.Imports). Absent from a build module that reports none.
 	Imports []string `json:"imports,omitempty"`
+	// OutOfStep are the generated files the build's compare found out of step with what their generator writes (the test
+	// step's `out-of-step`, answered by a trunk build's ask too): the builder carries them onto the build's end
+	// (BuildLogEntry.OutOfStep). Absent when none is, or from a build module that compares none.
+	OutOfStep []string `json:"out-of-step,omitempty"`
 }
 
 // AskBuilt is one artifact a build ask built.

go/delivery/version_numbered.go

@@ -0,0 +1,57 @@
+package delivery
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// The builder's event version.numbered (design 51 *Events of the builder*, *The floor*): said once per version the builder
+// numbers, on its own family `version` (seven days), apart from its builds' ends, so a waiter on a build's end does not
+// wake on it. A build module consumes it to publish a build's version with the held digest, which stores nothing.
+const (
+	// VersionNumberedEvent is the event's local name.
+	VersionNumberedEvent = "version.numbered"
+	// VersionNumberedSubject is its subject, as a consumer's filter names it.
+	VersionNumberedSubject = "mesh.mod." + BuilderModule + ".event." + VersionNumberedEvent
+)
+
+// VersionNumbered is the body of VersionNumberedEvent: a numbered version of a name, the build it was numbered for, and
+// what the build module needs to publish it.
+type VersionNumbered struct {
+	// Name is the numbered name, as builder_versions lists it; Kind its artifact's kind.
+	Name    string `json:"name"`
+	Kind    string `json:"kind"`
+	Version string `json:"version"`
+	Tag     string `json:"tag,omitempty"`
+	// Module and Fingerprint are the build the version was numbered for; Commit its source commit.
+	Module      string `json:"module"`
+	Fingerprint string `json:"fingerprint"`
+	Commit      string `json:"commit,omitempty"`
+	// Digest is the built artifact's, when the build held one; Seat the registry seat it is published through.
+	Digest string `json:"digest,omitempty"`
+	Seat   string `json:"seat,omitempty"`
+	// Head is the head the version answers, when it answers a tag ask.
+	Head string `json:"head,omitempty"`
+	// Again is when builder_publish_again said it once more, so the bus's dedup does not drop it.
+	Again string `json:"again,omitempty"`
+}
+
+// EncodeVersionNumbered writes the body, refusing one that names no name, version, module or fingerprint.
+func EncodeVersionNumbered(n VersionNumbered) ([]byte, error) {
+	if n.Name == "" || n.Version == "" || n.Module == "" || n.Fingerprint == "" {
+		return nil, fmt.Errorf("delivery: %s names its name, version, module and fingerprint", VersionNumberedEvent)
+	}
+	return json.Marshal(n)
+}
+
+// DecodeVersionNumbered reads the body, with the same refusal.
+func DecodeVersionNumbered(data []byte) (VersionNumbered, error) {
+	var n VersionNumbered
+	if err := json.Unmarshal(data, &n); err != nil {
+		return VersionNumbered{}, fmt.Errorf("delivery: %s is not readable: %w", VersionNumberedEvent, err)
+	}
+	if _, err := EncodeVersionNumbered(n); err != nil {
+		return VersionNumbered{}, err
+	}
+	return n, nil
+}