Merge remote-tracking branch 'origin/main' into fix/delivery-records-true

# Conflicts:
#	modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/main.go
#	modules/mesh-delivery-indexer/go.mod
#	modules/mesh-delivery-indexer/go.sum
#	modules/mesh-delivery-indexer/manifest_test.go
#	modules/mesh-delivery-indexer/module.json
#	modules/mesh-delivery-view/cmd/mesh-delivery-view-tools/main.go
#	modules/mesh-delivery-view/go.mod
#	modules/mesh-delivery-view/go.sum
#	modules/mesh-delivery-view/internal/view/read.go
#	modules/mesh-delivery-view/manifest_test.go
#	modules/mesh-delivery-view/module.json

modules/mesh-delivery-view/cmd/mesh-delivery-view-tools/main.go

@@ -62,6 +62,15 @@ func Tools(r view.Reader, u view.UsageReader) []stdio.Tool {
 				mods, err := r.Modules(only)
 				return map[string]any{"modules": mods}, err
 			}},
+		{Name: view.PlacementReadTool,
+			Description: "Where modules run, as the indexer read it from the catalogue's placement files at the last merge (placement.<node>, novox/hq ADR 0549): " +
+				"each node's modules in order with their host ports, bindings and settings placement, its pins and the seats its modules hold, and the catalogue revision. " +
+				"With node, that node's; with module, every node placing it; with neither, every node's. Keys that do not read are listed as unreadable. Read-only.",
+			Input: map[string]any{"type": "object", "properties": nodeModule},
+			Run: func(args map[string]any) (any, error) {
+				node, module := nodeModuleOf(args)
+				return r.Placement(node, module)
+			}},
 		{Name: view.CandidateReadTool,
 			Description: "What the indexer stored for one candidate (the open pull requests of a branch) under candidates.<group>, as stored: " +
 				"the pull requests and heads, the base, and per pull request the touched modules with their new-form fingerprint (fp2) or why " +
@@ -193,7 +202,8 @@ func read(state stdio.KeptState) view.StateRead {
 func main() {
 	r := view.Reader{State: read(stdio.State("mesh-delivery-indexer.modules")), Builds: read(stdio.State("mesh-delivery-builder.builds")), CandidatesState: read(stdio.State("mesh-delivery-indexer.candidates")),
 		WantsState: read(stdio.State("mesh-delivery-assigner.wants")), DifferencesState: read(stdio.State("mesh-delivery-assigner.differences")), HavesState: read(stdio.State("node-engine.have")),
-		ReachState: read(stdio.State("mesh-delivery-view.reach"))}
+		ReachState: read(stdio.State("mesh-delivery-view.reach")),
+		PlacementState: read(stdio.State("mesh-delivery-indexer.placement"))}
 	u := view.UsageReader{Haves: r.HavesState, Resolved: read(stdio.State("mesh-config.resolved")), Tries: read(stdio.State("mesh-delivery-checker.tries")),
 		Steps: map[string]view.StateRead{}, Pauses: map[string]view.StateRead{}, Backlog: backlogOf(socket())}
 	for _, lang := range delivery.AskLanguages {

modules/mesh-delivery-view/cmd/mesh-delivery-view-tools/main_test.go

@@ -105,6 +105,32 @@ func TestModulesToolAnswersEveryKeyAsStored(t *testing.T) {
 	if len(only) != 1 || string(only["b"]) != withNone {
 		t.Errorf("none2 modules = %v", only)
 	}
+
+	// 1126 (ADR 0549 §2): indexer_placement answers a node's key as stored, every node placing a module, or every node's,
+	// and lists a key that does not read.
+	const ace, g14 = `{"v":1,"node":"ace","revision":"m1","modules":[{"module":"plex"}]}`, `{"v":1,"node":"g14","revision":"m1","modules":[{"module":"zsh"},{"module":"plex"}]}`
+	p := view.Reader{PlacementState: fake{"placement.ace": ace, "placement.g14": g14, "placement.bad": `{"v":1}`, "other": "{}"}.reader().State}
+	got := func(args map[string]any) map[string]json.RawMessage {
+		t.Helper()
+		out, err := run(t, p, view.PlacementReadTool, args)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return out.(map[string]any)["placement"].(map[string]json.RawMessage)
+	}
+	if one := got(map[string]any{"node": "ace"}); len(one) != 1 || string(one["ace"]) != ace {
+		t.Errorf("node ace = %v", one)
+	}
+	if zsh := got(map[string]any{"module": "zsh"}); len(zsh) != 1 || string(zsh["g14"]) != g14 {
+		t.Errorf("module zsh = %v", zsh)
+	}
+	out, err = run(t, p, view.PlacementReadTool, map[string]any{})
+	if all := out.(map[string]any); err != nil || len(all["placement"].(map[string]json.RawMessage)) != 2 || len(all["unreadable"].([]string)) != 2 {
+		t.Errorf("every node = %v, %v", all, err)
+	}
+	if _, err := run(t, p, view.PlacementReadTool, map[string]any{"node": "novox"}); err == nil || !strings.Contains(err.Error(), "no placement of novox") {
+		t.Errorf("a node with no key: %v", err)
+	}
 }
 
 const (