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-mail-web/module.json.captured

@@ -0,0 +1,131 @@
+{
+  "module": "mesh-mail-web",
+  "version": "1",
+  "slug": "mail-web",
+  "runs-as": "mesh-mail-web",
+  "claims": [
+    {
+      "name": "mail-webclient",
+      "scope": "mesh",
+      "serves": ["open", "status"]
+    }
+  ],
+  "invokes": [
+    "seat:mail-store.accounts",
+    "seat:mail-store.search",
+    "seat:mail-store.read",
+    "seat:mail-store.send",
+    "seat:mail-store.send-status",
+    "seat:mail-reading.entries",
+    "seat:mail-reading.groups",
+    "seat:mail-reading.status",
+    "seat:mail-reading.correct",
+    "seat:mail-reading.lessons",
+    "seat:mail-reading.undo"
+  ],
+  "reads": ["mesh-mail.accounts"],
+  "requires": ["route", "oidc-client"],
+  "contributes": {
+    "route": {
+      "label": "mail",
+      "endpoint": "web"
+    },
+    "oidc-client": {
+      "label": "mail",
+      "endpoint": "web",
+      "callback": "/signed-in"
+    }
+  },
+  "binds": {
+    "route": "${dir:state}/route.json",
+    "oidc-client": "${dir:state}/oidc-bound.json"
+  },
+  "secrets": {
+    "oidc-client": "${dir:state}/oidc-bound.secret"
+  },
+  "listens": [
+    {
+      "name": "web",
+      "port": 8099,
+      "protocol": "tcp",
+      "from": "mesh",
+      "why": "the mail web client's pages, over http; only the route proxy reaches it, and the operator's own browser through the internal name (novox/hq ADR 0440 §2) — its public name, if any, is a route grant"
+    }
+  ],
+  "config": {
+    "operators": {
+      "type": "list",
+      "description": "The Keycloak identities (the ID token's preferred_username) let to sign in; nobody by default (novox/hq ADR 0440 §3).",
+      "trusted": true,
+      "default": []
+    }
+  },
+  "tools": [
+    "mail-webclient.open",
+    "mail-webclient.status",
+    "mail_web_health"
+  ],
+  "own-secrets": {
+    "broker": "${dir:state}/broker"
+  },
+  "secrets-owner": "mesh-mail-web",
+  "resources": [
+    {
+      "id": "account",
+      "type": "user",
+      "name": "mesh-mail-web",
+      "shell": "/usr/bin/nologin",
+      "home": "/var/lib/mesh-mail-web"
+    },
+    {
+      "id": "state",
+      "type": "directory",
+      "mode": "0700",
+      "owner": "mesh-mail-web",
+      "place": ".",
+      "unknown": "program"
+    },
+    {
+      "id": "operators",
+      "trusted": true,
+      "type": "file",
+      "path": "${dir:state}/operators.json",
+      "mode": "0600",
+      "owner": "mesh-mail-web",
+      "merge": "json",
+      "template": "files/operators.json",
+      "takes-config": ["operators"]
+    },
+    {
+      "id": "oidc-config",
+      "type": "file",
+      "path": "${dir:state}/oidc.json",
+      "mode": "0600",
+      "owner": "mesh-mail-web",
+      "template": "files/oidc.json"
+    }
+  ],
+  "build": {
+    "artifacts": [
+      {
+        "name": "tools",
+        "kind": "bundle",
+        "language": "go",
+        "system": "arch",
+        "from": "cmd/mesh-mail-web",
+        "binary": "mesh-mail-web",
+        "loads": ["mesh-mail-web"],
+        "env": {
+          "MESH_MAIL_WEB_OPERATORS": "${dir:state}/operators.json",
+          "MESH_MAIL_WEB_OIDC": "${dir:state}/oidc.json",
+          "MESH_MAIL_WEB_LISTEN": "${port:8099}"
+        }
+      },
+      {
+        "name": "files",
+        "kind": "archive",
+        "from": "files"
+      }
+    ]
+  }
+}