K1: mesh-build-go reads no kept state of the checker; the step ask carries the kept results (issue 1966)

A test step runs only the packages with no kept result for their digest, and the runner makes
that carry in the checker's place (ADR 0666 section 8; design 47 *Carried, not run* line 593 at
hq b229f5c4): the kept results reach the step in its ask (StepRun.kept, mesh-delivery
dc0df1b5), so the module's reads lose mesh-delivery-checker.kept and the lookup of the
checker's kept bucket goes. The carried and kept packages are in the step's end, on its step
key.

Milestone 47/G, research 086 area C (K1).

Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ

(Joined from 1c991294.)
Builds: design 47 G §25, §27, §66, §416 (BLD5)

Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ

modules/mesh-build-go/cmd/mesh-build-go/asks.go

@@ -2,13 +2,10 @@ package main
 
 import (
 	"context"
-	"encoding/json"
-	"fmt"
 	"path/filepath"
 	"time"
 
 	"git.novox.be/novox/mesh-catalog/modules/mesh-build-go/buildstep"
-	checkerseat "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshdeliverychecker"
 	seat "git.novox.be/novox/mesh-delivery/contracts/go/seats/nodebuildgo"
 	buildrun "git.novox.be/novox/mesh-delivery/sdk/buildrun"
 	sdkstep "git.novox.be/novox/mesh-delivery/sdk/buildstep"
@@ -24,13 +21,6 @@ import (
 // Seat is the node seat this module holds.
 const Seat = "node-build-go"
 
-// KeptState is the checker's kept verdicts, which a check ask takes for the packages whose digest has one (issue
-// 1887's design limit 1).
-const KeptState = checkerModule + "." + checkerseat.StateKept
-
-// checkerModule is the module that holds the seat mesh-delivery-checker, whose kept state a check ask reads.
-const checkerModule = "mesh-delivery-checker"
-
 // askSteps are the module's step bodies for an ask, each holding its workspace while it runs, as a tool's does.
 func (m *Module) askSteps(steps []StepTool) buildstep.AskSteps {
 	byName := map[string]buildstep.StepFunc{}
@@ -52,7 +42,8 @@ func (m *Module) askSteps(steps []StepTool) buildstep.AskSteps {
 			}
 			return sdkstep.ToolchainUsed{Version: installed, Recipe: m.Recipe.Version()}, nil
 		},
-		Kept:    m.KeptLookup,
+		// The kept results reach a test step in its ask (design 47 *Carried, not run*, line 593 at b229f5c4; issue 1966
+		// K1): this module reads no other part's kept state.
 		Has:     m.Has,
 		Release: func(ws string) error { return m.spaces().Release(ws) },
 		Logf:    m.Say,
@@ -62,29 +53,6 @@ func (m *Module) askSteps(steps []StepTool) buildstep.AskSteps {
 	}
 }
 
-// keptValue reads one key of the checker's kept state; nil when it is absent. Main sets it to the state's read; a test
-// its own.
-func (m *Module) keptValue(key string) (json.RawMessage, error) {
-	if m.ReadKept == nil {
-		return nil, nil
-	}
-	return m.ReadKept(key)
-}
-
-// KeptLookup is whether the checker kept a verdict for the level and digest, and how many tests it counted.
-func (m *Module) KeptLookup(ctx context.Context, level, digest string) (int, bool, error) {
-	key := checkerseat.KeptByLevelDigestKey(level, digest)
-	raw, err := m.keptValue(key)
-	if err != nil || raw == nil {
-		return 0, false, err
-	}
-	v, err := checkerseat.DecodeKeptByLevelDigestValue(raw)
-	if err != nil {
-		return 0, false, fmt.Errorf("%s holds what is not a kept verdict: %w", key, err)
-	}
-	return int(v.Tests), true, nil
-}
-
 // Puller is the module's pull of its seat's asks, on source (the runtime's seat pull when nil).
 func (m *Module) Puller(steps []StepTool, source buildstep.AskSource) *buildstep.Puller {
 	if source == nil {

modules/mesh-build-go/cmd/mesh-build-go/asks_test.go

@@ -114,15 +114,16 @@ func TestAtCapacityZeroNothingIsPulledAndTheToolsAnswer(t *testing.T) {
 
 func mustJSON(v any) []byte { b, _ := json.Marshal(v); return b }
 
-// 1887/A3go, A7: the manifest claims node-build-go serving its three verbs, reads the checker's kept verdicts and takes
+// 1887/A3go, A7: the manifest claims node-build-go serving its three verbs, reads no other part's state (issue 1966 K1: the kept
+// results come in the step ask) and takes
 // the node's build capacity as a setting, with the builder's default; the seat's verbs are served as its tools.
 func TestManifestClaimsTheGoBuildSeatAndReadsItsCapacity(t *testing.T) {
 	m := readManifest(t)
 	if len(m.Claims) != 1 || m.Claims[0].Name != Seat || !slices.Equal(m.Claims[0].Serves, []string{"current", "drop", "pause", "resume", "steps"}) {
 		t.Fatalf("claims = %+v", m.Claims)
 	}
-	if !slices.Contains(m.Reads, KeptState) {
-		t.Errorf("reads = %v lack %s", m.Reads, KeptState)
+	if len(m.Reads) != 0 {
+		t.Errorf("reads = %v, want none: the kept results come in the step ask", m.Reads)
 	}
 	raw, _ := os.ReadFile(moduleDir + "/module.json")
 	var doc struct {

modules/mesh-build-go/cmd/mesh-build-go/main.go

@@ -61,7 +61,6 @@ func main() {
 	m.Run = StepRunner(m.Home)
 	m.GoSeatFile = m.Home + "/go-package-registry.json"
 	m.Settings = m.Home + "/settings.json"
-	m.ReadKept = readOf(stdio.State(KeptState)).Get
 	m.ReadManifest = askManifest
 	m.AskInput = stdio.Ask
 	m.Probe = ProbeGo(m.Home, m.Cache)

modules/mesh-build-go/cmd/mesh-build-go/module.go

@@ -98,10 +98,9 @@ type Module struct {
 	Floor buildstep.Floor
 
 	// Settings is the module's settings file, which holds the node's build capacity (sdkstep.CapacitySetting); Capacity,
-	// when set, answers it instead (a test). ReadKept reads a key of the checker's kept state (KeptState).
+	// when set, answers it instead (a test).
 	Settings string
 	Capacity func() int
-	ReadKept func(key string) (json.RawMessage, error)
 	// SayStep says a pipeline step's end (buildstep.AskSteps.SayStep); the seat's publish on this node when nil.
 	SayStep func(sdkstep.StepEnded) error
 	// ReadManifest asks the delivery indexer's read tool (ManifestsTool) for one manifest by its key, which a compose ask's

modules/mesh-build-go/module.json

@@ -27,9 +27,6 @@
   "consumes": [
     "mesh-conditions.findings-asked"
   ],
-  "reads": [
-    "mesh-delivery-checker.kept"
-  ],
   "invokes": [
     "mesh-delivery-indexer.indexer_read_manifests",
     "seat:oci-artifact-registry.publish",