Capture mesh-catalog at feat/r4g (2246ccc4) with the templates its manifests name and its predefined.json, and lay the copy out as a repository's root

The catalogue's manifests moved their content into template files and fall back to predefined keys, so a copy of
module.json alone no longer passes the catalogue's own check; the bus's Dockerfile is gone from the catalogue.

testdata/beside/mesh-catalog/modules/model-usage/files/database.url

@@ -0,0 +1 @@
+postgresql://${bound:postgres-database:as}:${secret:postgres-database}@${bound:postgres-database:at}:${bound:postgres-database:port}/${bound:postgres-database:as}

testdata/beside/mesh-catalog/modules/model-usage/module.json.captured

@@ -43,19 +43,21 @@
       "id": "state",
       "type": "directory",
       "mode": "0700",
-      "place": "."
+      "place": ".",
+      "unknown": "program"
     },
     {
       "id": "database-url",
       "type": "file",
       "path": "${dir:state}/database.url",
       "mode": "0600",
-      "content": "postgresql://${bound:postgres-database:as}:${secret:postgres-database}@${bound:postgres-database:at}:${bound:postgres-database:port}/${bound:postgres-database:as}\n"
+      "template": "files/database.url"
     },
     {
       "id": "spool",
       "type": "directory",
-      "mode": "0700"
+      "mode": "0700",
+      "unknown": "program"
     },
     {
       "id": "prepare",
@@ -94,6 +96,11 @@
           "DATABASE_URL_FILE": "${dir:state}/database.url",
           "USAGE_SPOOL": "${dir:spool}"
         }
+      },
+      {
+        "name": "files",
+        "kind": "archive",
+        "from": "files"
       }
     ]
   }