R-8: the tool runner's own fingerprint reaches no bundle; a bundle reads the one its module is composed with

Builds: design 47 G §519, §618

Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h

node-tools/internal/runtime/own_account_test.go

@@ -38,6 +38,26 @@ func TestNoBusWordReachesABundle(t *testing.T) {
 	}
 }
 
+// design 47 G §618, §519: the runtime's own fingerprint reaches no bundle; the fingerprint a module's composed words hold does.
+func TestTheRuntimesOwnFingerprintReachesNoBundle(t *testing.T) {
+	base := []string{"MESH_FINGERPRINT=runner-build", "PATH=/usr/bin"}
+	for name, c := range map[string]struct {
+		given map[string]string
+		want  string
+	}{
+		"composed with none sees none":   {nil, ""},
+		"composed with one sees its own": {map[string]string{"MESH_FINGERPRINT": "module-build"}, "MESH_FINGERPRINT=module-build"},
+	} {
+		env := strings.Join(BundleEnv(base, c.given, "telegram", "anchor"), "\n")
+		if strings.Contains(env, "runner-build") {
+			t.Errorf("%s: the runtime's own fingerprint reached the bundle: %s", name, env)
+		}
+		if c.want == "" && strings.Contains(env, "MESH_FINGERPRINT") || !strings.Contains(env, c.want) {
+			t.Errorf("%s: the environment is %s", name, env)
+		}
+	}
+}
+
 // A tool call reaches only a tool's subject: whatever key a caller names, it is never a seat's event, accept
 // or proof — so no tool call says a choice, a link or a code, or submits an ask, in anybody's name.
 func TestAToolCallNeverReachesASeatsEventAcceptOrProof(t *testing.T) {