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/feh/README.md

@@ -45,3 +45,10 @@ setting once issue 168 closes, not a file the next push would overwrite.
 
 - `x11-display` and the `xinitrc` slot are ADR 0208's. Until the controller knows them, `mctl` reads
   them as unknown.
+
+## Its i3 lines are a contribution (changed 2026-10-05, novox/hq ADR 0212)
+
+The module no longer writes a file into i3's `config.d`. Its window-manager lines (the source is still
+under `files/i3/` where it had one) are a contribution to `node-display-session`. The i3 module places
+them in its own configuration under a `# <module>` line, so this module depends on a window manager
+being assigned beside it.

modules/feh/cmd/feh-tools/manifest_helpers_test.go

@@ -22,7 +22,9 @@ type manifest struct {
 	Environment  *environment     `json:"environment"`
 	Shell        []shellCode      `json:"shell"`
 	Resources    []map[string]any `json:"resources"`
-	Build        struct {
+	// Lines for other modules' seats (novox/hq ADR 0212): the window manager's, here.
+	Contributions []contribution `json:"contributions"`
+	Build         struct {
 		Artifacts []map[string]any `json:"artifacts"`
 	} `json:"build"`
 }
@@ -173,3 +175,32 @@ func checkNoSecretsOrInstallationNames(t *testing.T) {
 		}
 	}
 }
+
+type contribution struct {
+	Seat    string `json:"seat"`
+	Kind    string `json:"kind"`
+	Content string `json:"content"`
+}
+
+// i3Lines is what the module contributes to the window manager.
+func (m manifest) i3Lines() string {
+	var out string
+	for _, c := range m.Contributions {
+		if c.Seat == "node-display-session" && c.Kind == "config" {
+			out += c.Content
+		}
+	}
+	return out
+}
+
+// i3LinesAreSource checks the window-manager contribution is the source file it is written from.
+func (m manifest) i3LinesAreSource(t *testing.T, source string) {
+	t.Helper()
+	want, err := os.ReadFile(filepath.Join("..", "..", source))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if m.i3Lines() != string(want) {
+		t.Fatalf("the contribution to node-display-session is not %s: edit the source and copy it into module.json", source)
+	}
+}

modules/feh/cmd/feh-tools/manifest_test.go

@@ -63,11 +63,11 @@ func TestFehbgIsOwnedAndTheSessionStartRunsItOnce(t *testing.T) {
 
 func TestTheKeyThatRestoresTheWallpaperIsAnI3DropIn(t *testing.T) {
 	m := readManifest(t)
-	m.sameAsSource(t, "i3-bindings", "files/i3/50-feh.conf")
-	if p := m.resource(t, "i3-bindings")["path"]; p != "${machine:account-home}/.config/i3/config.d/50-feh.conf" {
+	m.i3LinesAreSource(t, "files/i3/50-feh.conf")
+	if p := m.i3Lines(); p == "" {
 		t.Fatalf("path: %v", p)
 	}
-	if c := m.resource(t, "i3-bindings")["content"].(string); !strings.Contains(c, "bindsym $mod+Shift+b exec --no-startup-id ~/.fehbg\n") {
+	if c := m.i3Lines(); !strings.Contains(c, "bindsym $mod+Shift+b exec --no-startup-id ~/.fehbg\n") {
 		t.Fatalf("%s", c)
 	}
 }

modules/feh/module.json

@@ -38,14 +38,6 @@
       "owner": "${machine:account}",
       "mode": "0755",
       "content": "#!/bin/sh\n# The wallpaper (module feh, novox/hq ADR 0208). Owned by the mesh: replaced at every push. The\n# session's start runs it, and so may anything that wants the declared wallpaper back. The image is\n# the module's own, in ~/.local/share/feh/wallpapers. feh_set changes the wallpaper for a session\n# without touching this file.\nfeh --no-fehbg --bg-fill \"$HOME/.local/share/feh/wallpapers/default.jpg\"\n"
-    },
-    {
-      "id": "i3-bindings",
-      "type": "file",
-      "path": "${machine:account-home}/.config/i3/config.d/50-feh.conf",
-      "owner": "${machine:account}",
-      "mode": "0644",
-      "content": "# The wallpaper's key (module feh, novox/hq ADR 0208). Owned by the mesh: replaced at every push.\n# It puts the declared wallpaper back, after a monitor change or a wallpaper set for the session.\nbindsym $mod+Shift+b exec --no-startup-id ~/.fehbg\n"
     }
   ],
   "build": {
@@ -67,5 +59,12 @@
         ]
       }
     ]
-  }
+  },
+  "contributions": [
+    {
+      "seat": "node-display-session",
+      "kind": "config",
+      "content": "# The wallpaper's key (module feh, novox/hq ADR 0208). Owned by the mesh: replaced at every push.\n# It puts the declared wallpaper back, after a monitor change or a wallpaper set for the session.\nbindsym $mod+Shift+b exec --no-startup-id ~/.fehbg\n"
+    }
+  ]
 }