Take the catalogue's composition rules into the node-engine

ADR 0593 §7: the composer with its refusals leaves mesh-sdk, so mesh-sdk
carries no composition rule. The catalogue functions only the
node-engine's composition reaches (Resolve, Resolution's Compose,
Declaration, DataItems, LeftOut, Rules and the rest, the settings,
placeholder and template refusals, the rendering helpers) are copied
with their tests into internal/compose/resolution; a method of a
mesh-sdk shape becomes a function taking it first. The composition
calls its own copies, and the captured catalogue its tests read lives
here now, shared by mesh-compose's tests.

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL

internal/compose/resolution/accesses_test.go

@@ -0,0 +1,80 @@
+package resolution
+
+import (
+	"strings"
+	"testing"
+
+	mcat "git.novox.be/novox/mesh-sdk/go/catalogue"
+)
+
+// The fault 04-ISSUES/036 records: a media stack is several modules — a library server, the
+// acquisition managers, a download client — that must share directories on one machine. Written
+// as owned `directory` resources, two of them on one node are refused as rivalrous owners, which
+// is right in general and wrong here: sharing those directories is the whole point of the stack.
+//
+// Declared as accesses to an operator-owned path (novox/hq ADR 0051), they co-resolve. An access
+// is not a resource and never enters the duplicate-owner map, so this is the exact case the
+// resolver refuses above when the same path is owned — and does not, when it is merely accessed.
+func TestTwoModulesAccessingOnePathCoResolve(t *testing.T) {
+	a := mod("a", nil, nil, nil)
+	a.Accesses = []mcat.Access{{Path: "/services/media/downloads", Mode: mcat.AccessReadWrite}}
+	b := mod("b", nil, nil, nil)
+	b.Accesses = []mcat.Access{{Path: "/services/media/downloads", Mode: mcat.AccessRead}}
+
+	got, err := Resolve(shelf(a, b), []string{"a", "b"}, workstation(), mcat.World{})
+	if err != nil {
+		t.Fatalf("two modules accessing one operator-owned path were refused: %v", err)
+	}
+
+	// And each accessing module's grant reaches the machine as its own `access` resource, so the
+	// host can find the path present or refuse — both naming the one operator-owned path.
+	var accesses int
+	for _, r := range mustDeclare(t, got) {
+		if r["type"] == "access" && r["path"] == "/services/media/downloads" {
+			accesses++
+		}
+	}
+	if accesses != 2 {
+		t.Errorf("expected both modules' accesses in the declaration, got %d", accesses)
+	}
+}
+
+// The mirror of the case above, so the sharing vocabulary does not weaken the rule it sits beside:
+// two modules OWNING one path is still refused, exactly as before accesses existed.
+func TestTwoModulesOwningOnePathAreStillRefused(t *testing.T) {
+	a := mod("a", nil, nil, nil)
+	a.Resources = []map[string]any{
+		{"id": "lib", "type": "directory", "path": "/services/media/movies", "mode": "0755"}}
+	b := mod("b", nil, nil, nil)
+	b.Resources = []map[string]any{
+		{"id": "lib", "type": "directory", "path": "/services/media/movies", "mode": "0755"}}
+
+	_, err := Resolve(shelf(a, b), []string{"a", "b"}, workstation(), mcat.World{})
+	if err == nil {
+		t.Fatal("two modules owning the same directory were both assigned")
+	}
+	if !strings.Contains(err.Error(), "/services/media/movies") {
+		t.Errorf("the refusal does not name the path: %v", err)
+	}
+}
+
+// Shared data is the operator's, owned by no module (novox/hq ADR 0051). A module owning the path
+// another module was told to expect the operator to provide would create and chown it — and the
+// two intentions cannot both hold, so it is refused by name. This is what keeps the distinction
+// machine-checkable rather than a convention nobody enforces.
+func TestAModuleMayNotOwnWhatAnotherAccesses(t *testing.T) {
+	owns := mod("owns", nil, nil, nil)
+	owns.Resources = []map[string]any{
+		{"id": "lib", "type": "directory", "path": "/services/media/movies", "mode": "0755"}}
+	uses := mod("uses", nil, nil, nil)
+	uses.Accesses = []mcat.Access{{Path: "/services/media/movies", Mode: mcat.AccessRead}}
+
+	_, err := Resolve(shelf(owns, uses), []string{"owns", "uses"}, workstation(), mcat.World{})
+	if err == nil {
+		t.Fatal("a module owning a path another accesses was allowed")
+	}
+	if !strings.Contains(err.Error(), "/services/media/movies") ||
+		!strings.Contains(err.Error(), "the operator's") {
+		t.Errorf("the refusal does not explain the ownership conflict: %v", err)
+	}
+}