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/showcase/files/README.md

@@ -0,0 +1,6 @@
+# showcase's packed files
+
+Packed as an `archive` artifact and unpacked onto the machine by an `archive` resource.
+
+This exists to exercise the case inlining cannot serve: a tree of files that belongs on a machine
+and would make a declaration enormous if it were carried inside one.

testdata/beside/mesh-catalog/modules/showcase/files/marker.txt

@@ -0,0 +1 @@
+showcase

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

@@ -1,6 +1,7 @@
 {
   "module": "showcase",
   "version": "1",
+  "templates": "templates",
   "slug": "show",
   "capabilities": [
     "container-runtime"
@@ -74,6 +75,11 @@
         "name": "helper",
         "kind": "upstream",
         "from": "alpine@sha256:28bd5fe8b56d1bd048e5babf5b10710ebe0bae67db86916198a6eec434943f8b"
+      },
+      {
+        "name": "templates",
+        "kind": "archive",
+        "from": "templates"
       }
     ]
   },
@@ -95,26 +101,29 @@
       "id": "mesh-state",
       "type": "directory",
       "mode": "0700",
-      "place": "mesh"
+      "place": "mesh",
+      "unknown": "program"
     },
     {
       "id": "state",
       "type": "directory",
       "mode": "0755",
-      "place": "."
+      "place": ".",
+      "unknown": "program"
     },
     {
       "id": "settings",
       "type": "file",
       "path": "${dir:state}/showcase.env",
       "mode": "0600",
-      "content": "SHOWCASE_GREETING=hello\nSHOWCASE_EVERY_SECONDS=30\nSHOWCASE_STATE=/var/lib/showcase\nSHOWCASE_DATABASE=${bound:postgres-database:at}\nSHOWCASE_LISTEN=${port:8080}\n"
+      "template": "templates/showcase.env"
     },
     {
       "id": "packed",
       "type": "archive",
       "path": "/opt/showcase",
-      "artifact": "files"
+      "artifact": "files",
+      "unknown": "program"
     },
     {
       "id": "net",

testdata/beside/mesh-catalog/modules/showcase/templates/showcase.env

@@ -0,0 +1,5 @@
+SHOWCASE_GREETING=hello
+SHOWCASE_EVERY_SECONDS=30
+SHOWCASE_STATE=/var/lib/showcase
+SHOWCASE_DATABASE=${bound:postgres-database:at}
+SHOWCASE_LISTEN=${port:8080}