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/nftables/files/mesh-filter.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=The mesh's packet filter, derived from what is assigned to this node
+Wants=network-pre.target
+Before=network-pre.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=nft -f /etc/nftables.conf
+ExecReload=nft -f /etc/nftables.conf
+ExecStop=nft delete table inet mesh
+
+[Install]
+WantedBy=multi-user.target

testdata/beside/mesh-catalog/modules/nftables/files/mesh.conf

@@ -0,0 +1,5 @@
+# The mesh: stopping the stock unit deletes only the mesh's table, never the whole ruleset
+# (novox/hq ADR 0100) — a flush would take the container runtime's rules and any firewall with it.
+[Service]
+ExecStop=
+ExecStop=nft delete table inet mesh