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/searxng/files/settings.yml

@@ -0,0 +1,16 @@
+{
+  "use_default_settings": true,
+  "server": {
+    "secret_key": "${secret:secret}",
+    "base_url": false,
+    "limiter": false,
+    "image_proxy": false,
+    "public_instance": false
+  },
+  "search": {
+    "formats": ["html", "json"]
+  },
+  "valkey": {
+    "url": "valkey://valkey:6379/0"
+  }
+}