The node-engine owns the composition it alone runs (H1, H2)

ADR 0593 §1 and §7: compose, its bus reader and runtime reader, takein,
validate, the overlay generator, the composer's run and mesh-compose, and
the judgement of a move leave mesh-sdk for the node-engine's internal
packages, so no other module composes and a change to them rebuilds only
the node-engine. The shapes others read (the composer's request and
verdict, the overlay's names, compositions and answers) stay in mesh-sdk.
The node's grant is now a golden file of what the grants part composes,
since the composer of the bus's user list leaves mesh-sdk too.

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

cmd/mesh-compose/testdata/mesh-catalog/modules/mesh-reads/module.json.captured

@@ -0,0 +1,55 @@
+{
+  "module": "mesh-reads",
+  "version": "1",
+  "runs-as": "mesh-reads",
+  "claims": [
+    {
+      "name": "node-reads",
+      "scope": "node",
+      "serves": [
+        "stat",
+        "readlink",
+        "list",
+        "read",
+        "search",
+        "account"
+      ]
+    }
+  ],
+  "own-secrets": {
+    "broker": "${dir:state}/broker"
+  },
+  "secrets-owner": "mesh-reads",
+  "resources": [
+    {
+      "id": "account",
+      "type": "user",
+      "name": "mesh-reads",
+      "shell": "/usr/bin/nologin",
+      "home": "/var/lib/mesh-reads"
+    },
+    {
+      "id": "state",
+      "type": "directory",
+      "mode": "0700",
+      "owner": "mesh-reads",
+      "place": ".",
+      "unknown": "program"
+    }
+  ],
+  "build": {
+    "artifacts": [
+      {
+        "name": "tools",
+        "kind": "bundle",
+        "language": "go",
+        "system": "arch",
+        "from": "cmd/mesh-reads",
+        "binary": "mesh-reads",
+        "loads": [
+          "mesh-reads"
+        ]
+      }
+    ]
+  }
+}