Send a merge's builds to every machine at once, with no first-machine gate (hq ADR 0360)

The operator chose the leanest rollout: no gate, no one machine first, failures loud and fixed forward.
A walk sends every rolled-out module to every machine running it in one step, built-by orders no tier,
and a walk ends on its machines' reports. The backlog walk sends every machine at once and passes each
on its applied report.

cmd/mesh-controller/release_plan.go

@@ -43,29 +43,15 @@ func tiersOf(set []string, edges []inventory.Edge) [][]string {
 	for _, m := range set {
 		deps[m] = map[string]bool{}
 	}
-	// The build seat's holders follow the controller that defines their worker (EdgeWorkerOf,
-	// novox/hq issue 206), so the built-by edge from that controller to such a holder yields: the
-	// controller is built by whichever build machine is running, as the runtime image always was.
-	worker := map[string]map[string]bool{}
-	for _, e := range edges {
-		if e.Kind == inventory.EdgeWorkerOf && in[e.From] && in[e.To] {
-			if worker[e.To] == nil {
-				worker[e.To] = map[string]bool{}
-			}
-			worker[e.To][e.From] = true
-		}
-	}
 	for _, e := range edges {
 		// A code dependency — B packages A's source — rebuilds B with A, in the same tier: B's
-		// build needs nothing of A's first. The other kinds order: stands-on and declared after
-		// the base is built, built-by after the build machine is built and running — except for
-		// what the build machine itself stands on, and for the controller whose worker the build
-		// machine binds. The runtime image is built by the builder and the builder is built on the
-		// runtime image; the image comes first, built by the builder that is running.
+		// build needs nothing of A's first. Stands-on and declared order after the base is built, and the
+		// build seat's holder follows the controller that defines its worker (EdgeWorkerOf, issue 206).
 		if !in[e.From] || !in[e.To] || e.From == e.To || e.Kind == inventory.EdgePackages {
 			continue
 		}
-		if e.Kind == inventory.EdgeBuiltBy && (isBaseOf(e.From, e.To, edges, in) || worker[e.From][e.To]) {
+		// **Being built by the builder orders nothing** (novox/hq ADR 0360 §3): whichever builder runs builds it.
+		if e.Kind == inventory.EdgeBuiltBy {
 			continue
 		}
 		deps[e.From][e.To] = true
@@ -106,29 +92,6 @@ func tiersOf(set []string, edges []inventory.Edge) [][]string {
 	return tiers
 }
 
-// isBaseOf says whether `to` stands on `base`, directly or through other bases in the set, along
-// the build edges alone.
-func isBaseOf(base, to string, edges []inventory.Edge, in map[string]bool) bool {
-	seen := map[string]bool{}
-	var walk func(string) bool
-	walk = func(m string) bool {
-		if m == base {
-			return true
-		}
-		if seen[m] {
-			return false
-		}
-		seen[m] = true
-		for _, e := range edges {
-			if e.From == m && in[e.To] && (e.Kind == inventory.EdgeStandsOn || e.Kind == inventory.EdgeDeclared) && walk(e.To) {
-				return true
-			}
-		}
-		return false
-	}
-	return walk(to)
-}
-
 // reachableFrom is the moved modules plus everything that depends on them, through every layer:
 // what a merge rebuilds. Along the code and build edges only: a module *built by* the build machine
 // is not changed by a new build machine, so a built-by edge orders and gates a plan and never
@@ -164,7 +127,7 @@ func reachableFrom(moved []string, edges []inventory.Edge) []string {
 }
 
 // hasCycle says whether the tiers' last tier holds modules that still depend on each other. A packages
-// edge orders nothing (tiersOf), so a module and what packages its source share a tier by rule: that is
+// or built-by edge orders nothing (tiersOf), so a module and what packages its source share a tier by rule: that is
 // no cycle, and saying one was is a false report in every such plan's log.
 func hasCycle(tiers [][]string, edges []inventory.Edge) bool {
 	if len(tiers) == 0 {
@@ -175,7 +138,7 @@ func hasCycle(tiers [][]string, edges []inventory.Edge) bool {
 		last[m] = true
 	}
 	for _, e := range edges {
-		if e.Kind == inventory.EdgePackages {
+		if e.Kind == inventory.EdgePackages || e.Kind == inventory.EdgeBuiltBy {
 			continue
 		}
 		if last[e.From] && last[e.To] {
@@ -221,12 +184,6 @@ func gates(p inventory.Plan, edges []inventory.Edge, rollsOut func(string) bool)
 		return nil
 	}
 	inTier := map[string]bool{}
-	all := map[string]bool{}
-	for _, tier := range p.Tiers {
-		for _, m := range tier {
-			all[m] = true
-		}
-	}
 	for _, m := range p.Tiers[p.Tier] {
 		inTier[m] = true
 	}
@@ -241,8 +198,8 @@ func gates(p inventory.Plan, edges []inventory.Edge, rollsOut func(string) bool)
 	for _, e := range edges {
 		// A delivery group's order inside a walk (novox/hq ADR 0276 decision 5) gates as built-by does: the
 		// member before is running on its machines before the member after is asked.
-		ordered := e.Kind == edgeGroupOrder ||
-			e.Kind == inventory.EdgeBuiltBy && !isBaseOf(e.From, e.To, edges, all)
+		// A built-by edge waits for nothing since novox/hq ADR 0360 §3.
+		ordered := e.Kind == edgeGroupOrder
 		if later[e.From] && inTier[e.To] && ordered && !seen[e.To] && rollsOut(e.To) {
 			seen[e.To] = true
 			out = append(out, e.To)
@@ -888,6 +845,9 @@ func advanceOnce(ctx context.Context, open *stores, p *inventory.Plan,
 		if err != nil {
 			return false, err
 		}
+		// **Every machine at once** (novox/hq ADR 0360 §1, §2): a module that rolls out is sent to every machine
+		// running it in one step, with no first machine and no gate, whatever module it is.
+		policy.Together = true
 		var reports []inventory.Reported
 		if !policy.Together {
 			// Read for the choice of the first machine as well as for its report.
@@ -1117,15 +1077,87 @@ func advanceOnce(ctx context.Context, open *stores, p *inventory.Plan,
 			return changed, nil
 		}
 	}
+	// **A walk ends on its machines' reports** (novox/hq ADR 0360 §4, §5): after its last tier, every machine it sent
+	// has reported on that send, or is silent past ApplySilentAfter; never a health reading.
+	end := ""
+	if p.Tier == len(p.Tiers)-1 {
+		reports, err := inv.LastReports(ctx)
+		if err != nil {
+			return false, err
+		}
+		waiting, failed, silent := walkReports(*p, reports, time.Now().UTC())
+		if len(waiting) > 0 {
+			note := "sent; waiting for " + strings.Join(waiting, ", ") + " to report on their send"
+			changed := p.State != inventory.PlanRolling || p.Note != note
+			p.State = inventory.PlanRolling
+			p.Note = note
+			return changed, nil
+		}
+		var said []string
+		if len(failed) > 0 {
+			said = append(said, "failed or refused its send (apply-failing says it): "+strings.Join(failed, ", "))
+		}
+		if len(silent) > 0 {
+			said = append(said, fmt.Sprintf("said nothing on its send within %s: %s", inventory.ApplySilentAfter,
+				strings.Join(silent, ", ")))
+		}
+		end = strings.Join(said, "; ")
+	}
 	p.Tier++
 	p.State = inventory.PlanBuilding
-	p.Note = ""
+	p.Note = end
 	if p.Tier < len(p.Tiers) {
 		fmt.Printf("%s: tier %d done; asking tier %d: %s\n", p.ID, p.Tier-1, p.Tier, strings.Join(p.Tiers[p.Tier], ", "))
 	}
 	return true, nil
 }
 
+// walkReports is, for every machine a walk sent its rest, whether it reported on that send (novox/hq ADR 0360 §4):
+// those still waiting, those that reported a failed or refused apply, and those silent past ApplySilentAfter,
+// each sorted. Pure.
+func walkReports(p inventory.Plan, reports []inventory.Reported, now time.Time) (waiting, failed, silent []string) {
+	byNode := map[string]inventory.Reported{}
+	for _, r := range reports {
+		byNode[r.Node] = r
+	}
+	seen := map[string]bool{}
+	for _, s := range p.Modules {
+		if s == nil {
+			continue
+		}
+		for node, sent := range s.Rest {
+			if seen[node] {
+				continue
+			}
+			r := byNode[node]
+			at := sent.At
+			if at.IsZero() && s.SentAt != nil {
+				at = *s.SentAt
+			}
+			switch {
+			case r.At != nil && sent.ReportsOn(r):
+				seen[node] = true
+				if r.Outcome == inventory.OutcomeFailed || r.Outcome == inventory.OutcomeRefused {
+					failed = append(failed, node)
+				}
+			case !at.IsZero() && now.Sub(at) > inventory.ApplySilentAfter:
+				seen[node] = true
+				silent = append(silent, node)
+			default:
+				if !slices.Contains(waiting, node) {
+					waiting = append(waiting, node)
+				}
+			}
+		}
+	}
+	// A machine one module's send was reported on and another's not yet is the same send: reported.
+	waiting = slices.DeleteFunc(waiting, func(n string) bool { return seen[n] })
+	sort.Strings(waiting)
+	sort.Strings(failed)
+	sort.Strings(silent)
+	return waiting, failed, silent
+}
+
 // restOf is, for one module, every machine of its rest that the send reached and what it carried there.
 func restOf(to, sent []string, what map[string]inventory.SentDeclaration) map[string]inventory.SentDeclaration {
 	out := map[string]inventory.SentDeclaration{}