i3: other modules' lines are contributions to node-display-session (hq ADR 0212)

rofi, clipmenu, feh, i3status-rust and the laptop's model module wrote files into i3's config.d,
naming no dependency on the window manager. They now contribute their lines; i3 places them under a
line naming each module, and config.d is the operator's alone. The catalogue-wide test composes the
contributions as the controller does and checks the whole with i3 -C.

modules/clipmenu/module.json

@@ -48,14 +48,6 @@
       "package": "rofi-greenclip",
       "absent": true
     },
-    {
-      "id": "i3-bindings",
-      "type": "file",
-      "path": "${machine:account-home}/.config/i3/config.d/50-clipmenu.conf",
-      "owner": "${machine:account}",
-      "mode": "0644",
-      "content": "# The clipboard's history key (module clipmenu, novox/hq ADR 0208). Owned by the mesh: replaced at\n# every push. clipmenu shows the history through `dmenu`, the node's dmenu-compatible command, which\n# the holder of node-launcher answers (rofi on the workstations); the chosen entry is put back on the\n# clipboard.\nbindsym $mod+period exec --no-startup-id clipmenu -p Clipboard\n"
-    },
     {
       "id": "text-only",
       "type": "file",
@@ -78,5 +70,12 @@
         ]
       }
     ]
-  }
+  },
+  "contributions": [
+    {
+      "seat": "node-display-session",
+      "kind": "config",
+      "content": "# The clipboard's history key (module clipmenu, novox/hq ADR 0208). Owned by the mesh: replaced at\n# every push. clipmenu shows the history through `dmenu`, the node's dmenu-compatible command, which\n# the holder of node-launcher answers (rofi on the workstations); the chosen entry is put back on the\n# clipboard.\nbindsym $mod+period exec --no-startup-id clipmenu -p Clipboard\n"
+    }
+  ]
 }