Judge tests that read another repository against what the check clones, never the desktop's checkout (issue 432)

Tests that read ../../../mesh-catalog or ../../../mesh-host gave a verdict
that depended on what sat beside the checkout: a stale or dirty sibling
failed them on a desktop, and a missing one skipped them unseen. They now
read the clone the build seat puts in MESH_CHECK_BESIDE, failing when it is
absent there, and elsewhere a copy captured at a named commit.

The skip had hidden that the builder test read a module retired by ADR 0190.
The systemd reading test no longer counts the machine's own environment.d.

cmd/mesh-controller/check_test.go

@@ -6,8 +6,10 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/novox/mesh-controller/internal/catalogue"
 	"testing"
+
+	"github.com/novox/mesh-controller/internal/beside"
+	"github.com/novox/mesh-controller/internal/catalogue"
 )
 
 // The check anybody can run is the check registration runs (novox/hq issue 148, ADR 0037): a manifest
@@ -56,10 +58,7 @@ func TestModuleCheckJudgesBetweenTheManifestsGiven(t *testing.T) {
 
 // The real catalogue passes the command, the way it passes the test that used to be the only check.
 func TestModuleCheckPassesTheCatalogue(t *testing.T) {
-	root := filepath.Join("..", "..", "..", "mesh-catalog", "modules")
-	if _, err := os.Stat(root); err != nil {
-		t.Skipf("catalogue sibling not present: %v", err)
-	}
+	root := beside.Catalogue(t)
 	paths, err := manifestsUnder(root)
 	if err != nil || len(paths) == 0 {
 		t.Fatalf("no manifests under %s: %v", root, err)

cmd/mesh-controller/network_test.go

@@ -3,10 +3,12 @@ package main
 import (
 	"context"
 	"os"
+	"path/filepath"
 	"reflect"
 	"strings"
 	"testing"
 
+	"github.com/novox/mesh-controller/internal/beside"
 	"github.com/novox/mesh-controller/internal/catalogue"
 	"github.com/novox/mesh-controller/internal/inventory"
 	"github.com/novox/mesh-controller/internal/overlay"
@@ -239,13 +241,12 @@ func TestATakeoverIsNotComposedForAHubPlacedOffItsTunnel(t *testing.T) {
 	}
 }
 
-// theResolver is the catalogue's dnsmasq module as it is, or the test is skipped where the
-// catalogue is not beside this checkout.
+// theResolver is the catalogue's dnsmasq module as it is (internal/beside).
 func theResolver(t *testing.T) catalogue.Manifest {
 	t.Helper()
-	raw, err := os.ReadFile("../../../mesh-catalog/modules/dnsmasq/module.json")
+	raw, err := os.ReadFile(filepath.Join(beside.Catalogue(t), "dnsmasq", "module.json"))
 	if err != nil {
-		t.Skipf("the catalogue is not beside this checkout: %v", err)
+		t.Fatal(err)
 	}
 	m, err := catalogue.ParseManifest(raw)
 	if err != nil {