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/lemurs/files/xserver

@@ -0,0 +1,8 @@
+#!/bin/sh
+# The X server as lemurs starts it, written by the mesh (module lemurs). Replaced at every push.
+#
+# -noreset: without it, X resets whenever its last client disconnects, and a reset empties the
+# resource database. The session's start merges the X resources with xrdb before any long-lived
+# client is connected, so the server reset twice in the four seconds after a login and threw the
+# resources away: xterm fell back to the bitmap "fixed" font, without the mesh's face and colours.
+exec /usr/bin/X "$@" -noreset