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/kernel/files/mesh-kernel-boot-entries.service

@@ -0,0 +1,22 @@
+[Unit]
+Description=The fallback kernel's place on this machine's boot menu
+# Module kernel, novox/hq ADR 0508 §9, issue 1841. Starting this unit reads which loader booted the machine and
+# places the fallback kernel's boot entry (systemd-boot) or generates the menu again (GRUB); it fails, and says
+# why, when there is no loader or the boot partition has no room. The kernel packages are declared after this
+# unit, so the entry is in place before they are installed.
+After=local-fs.target
+Wants=local-fs.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=${dir:state}/boot-entries run
+# It writes the boot partition, the pacman hook directory and its own state, and nothing else.
+ProtectSystem=strict
+ReadWritePaths=/boot ${dir:state} /etc/pacman.d/hooks
+ProtectHome=yes
+PrivateNetwork=yes
+NoNewPrivileges=yes
+
+[Install]
+WantedBy=multi-user.target