lemurs, i3status-rust: what the first assignment refused

The host refuses boot on a service that leaves its state to the machine, so lemurs.service
is declared running (no trigger, so a push still never restarts it). pacman-contrib is the
pacman module's, and two modules declaring one package make a node unresolvable.

modules/i3status-rust/README.md

@@ -2,7 +2,7 @@
 
 The bars as a module (novox/hq ADR 0208, research 026/05).
 
-- Installs `i3status-rust`, and `pacman-contrib` for `checkupdates`, which the update block uses.
+- Installs `i3status-rust`. The update block's `checkupdates` comes from `pacman-contrib`, which the `pacman` module installs on every node; two modules declaring one package is refused at composition.
   Claims the mesh's `node-bar` seat (no verbs yet, ADR 0208 §2). Requires `x11-display` on its own
   machine: its bars are i3bar's.
 - Owns `~/.config/i3status-rust/`, both bars (`top-bar.toml`, `bottom-bar.toml`) and their icon set
@@ -82,5 +82,5 @@ Until one of them is chosen, **the laptop's bar shows no battery** once this mod
 - The battery block waits for one of the two ways above.
 - The watchdog would be a user unit once user-scoped units ship (mesh-host #72). It is not, because it
   runs per session and ends with the session, as a session-start line already does.
-- `pacman-contrib` is declared here. A future `pacman` module that wants `checkupdates` or `paccache`
-  takes it over, since a package is declared once per node.
+- `pacman-contrib` is the `pacman` module's, which took it over as foreseen: a package is declared
+  once per node.

modules/i3status-rust/cmd/i3status-rust-tools/manifest_test.go

@@ -22,7 +22,7 @@ func TestItClaimsTheBarSeatAndRequiresTheXDisplay(t *testing.T) {
 	if !reflect.DeepEqual(m.Requires, []string{"x11-display"}) {
 		t.Fatalf("requires: %v", m.Requires)
 	}
-	if present, absent := m.packages(); !reflect.DeepEqual(present, []string{"i3status-rust", "pacman-contrib"}) || absent != nil {
+	if present, absent := m.packages(); !reflect.DeepEqual(present, []string{"i3status-rust"}) || absent != nil {
 		t.Fatalf("packages: %v, absent %v", present, absent)
 	}
 }

modules/i3status-rust/module.json

@@ -32,11 +32,6 @@
       "type": "package",
       "package": "i3status-rust"
     },
-    {
-      "id": "update-check",
-      "type": "package",
-      "package": "pacman-contrib"
-    },
     {
       "id": "configuration-dir",
       "type": "directory",