feat: Add simple routing class, b=no-bug, c=no-component

src/zen/moz.build

@@ -15,5 +15,6 @@ DIRS += [
     "urlbar",
     "toolkit",
     "sessionstore",
+    "space-routing",
     "share",
 ]

src/zen/space-routing/ZenSpaceRouting.sys.mjs

@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { JSONFile } from "resource://gre/modules/JSONFile.sys.mjs";
+
+class nsZenSpaceRouting {
+  #jsonFile = null;
+
+  constructor() {
+    this.#jsonFile = new JSONFile({
+      path: PathUtils.join(PathUtils.profileDir, "space-routing.json"),
+    });
+  }
+}
+
+export var ZenSpaceRouting = new nsZenSpaceRouting();

src/zen/space-routing/moz.build

@@ -0,0 +1,7 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXTRA_JS_MODULES.zen += [
+  "ZenSpaceRouting.sys.mjs",
+]