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/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)
 	}
 }