fix(nix): restore desktop app icon matching (#2506)

* fix(nix): identify desktop app for icon matching

* fix(desktop): ignore wrapper class in CLI passthrough

* fix(nix): give the Electron launcher a real app root

The Wayland app_id — what a bar or taskbar uses to find the .desktop
entry, and therefore the icon — is fixed during Electron startup, so
neither `--class=` nor main.ts's `app.setName()` reaches it on current
Electron. Launching `electron path/to/main.js` gives Electron no
package.json to read a name from, so the window published the default
"electron" app_id and shells drew the generic Electron icon.

Launch a one-file app root named "paseo-desktop" instead, matching the
installed desktop entry and hicolor icon. Older Electron (38) derives
the app_id from the runtime app name "Paseo", so also ship a NoDisplay
alias entry under that name; the icon resolves either way and the
launcher list still shows a single Paseo.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

packages/desktop/src/daemon/cli/passthrough.test.ts

@@ -65,6 +65,23 @@ describe("passthrough CLI", () => {
     ).toBeNull();
   });
 
+  it("ignores Linux desktop identity arguments injected by the Nix wrapper", () => {
+    expect(
+      parsePassthroughCliArgs({
+        argv: [
+          "/nix/store/electron/bin/electron",
+          "/nix/store/paseo-desktop/share/paseo-desktop/electron-app",
+          "--no-sandbox",
+          "--class=paseo-desktop",
+          "daemon",
+          "status",
+        ],
+        isDefaultApp: true,
+        forceCli: false,
+      }),
+    ).toEqual(["daemon", "status"]);
+  });
+
   it("ignores Electron remote debugging switches", () => {
     expect(
       parsePassthroughCliArgs({

packages/desktop/src/daemon/cli/passthrough.ts

@@ -2,7 +2,7 @@ import { pathToFileURL } from "node:url";
 import { resolvePassthroughCliEntrypoint } from "./entrypoints.js";
 
 const DESKTOP_CLI_ENV = "PASEO_DESKTOP_CLI";
-const IGNORED_ARG_PREFIXES = ["-psn_", "--no-sandbox", "--remote-debugging-port="];
+const IGNORED_ARG_PREFIXES = ["-psn_", "--class=", "--no-sandbox", "--remote-debugging-port="];
 
 export type PassthroughCliRunner = (argv: string[]) => Promise<number>;