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.

testdata/beside/mesh-catalog/modules/powerlevel10k/module.json.captured

@@ -0,0 +1,41 @@
+{
+  "module": "powerlevel10k",
+  "version": "1",
+  "shell": [
+    {
+      "for": "zsh",
+      "slot": "normal",
+      "code": "# The prompt: powerlevel10k v1.20.0, pinned in this module (novox/hq ADR 0205), and its configuration.\n[[ ! -f ~/.local/share/powerlevel10k/powerlevel10k.zsh-theme ]] || source ~/.local/share/powerlevel10k/powerlevel10k.zsh-theme\n[[ ! -f ~/.config/powerlevel10k/p10k.zsh ]] || source ~/.config/powerlevel10k/p10k.zsh\n"
+    }
+  ],
+  "resources": [
+    {
+      "id": "theme",
+      "type": "archive",
+      "path": "${machine:account-home}/.local/share/powerlevel10k",
+      "owner": "${machine:account}",
+      "artifact": "theme"
+    },
+    {
+      "id": "configuration",
+      "type": "archive",
+      "path": "${machine:account-home}/.config/powerlevel10k",
+      "owner": "${machine:account}",
+      "artifact": "configuration"
+    }
+  ],
+  "build": {
+    "artifacts": [
+      {
+        "name": "theme",
+        "kind": "archive",
+        "from": "theme"
+      },
+      {
+        "name": "configuration",
+        "kind": "archive",
+        "from": "config"
+      }
+    ]
+  }
+}