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/predefined.json

@@ -0,0 +1,18 @@
+{
+  "agent-managed-settings": {
+    "type": "object",
+    "description": "The managed settings every agent session on a node is held to (Claude Code's managed-settings.json), as a JSON object.",
+    "trusted": true
+  },
+  "font-size": {
+    "type": "number",
+    "description": "The size a desktop program shows its text in, in points.",
+    "minimum": 6,
+    "maximum": 72
+  },
+  "upgrade-order": {
+    "type": "list",
+    "description": "The nodes in the order they upgrade, each by its name: the first opens each week's round of upgrades, and each node upgrades only after the one before it passed its after-upgrade check. Empty or unset: no round starts.",
+    "trusted": true
+  }
+}