add dev rules

src/paths.js

@@ -114,6 +114,22 @@ function resolvePortablePath(p) {
   return path.join(FILES, p)
 }
 
+// The launcher's own icon (renderer/plwl.png), used by the tray, the app
+// icon and as the .desktop shortcut fallback. Cached: it never moves at
+// runtime.
+let launcherIcon = null
+function launcherIconPath() {
+  if (launcherIcon === null) {
+    const p = path.join(APP_ROOT, 'renderer', 'plwl.png')
+    try {
+      launcherIcon = fs.existsSync(p) ? p : ''
+    } catch {
+      launcherIcon = ''
+    }
+  }
+  return launcherIcon || null
+}
+
 function readJson(file, fallback) {
   try {
     return JSON.parse(fs.readFileSync(file, 'utf8'))
@@ -129,4 +145,4 @@ function writeJson(file, data) {
   fs.renameSync(tmp, file)
 }
 
-module.exports = { RESOURCES, APP_ROOT, BUILD, FILES, DATA, DIRS, ensureDirs, syncBundledTranslations, readJson, writeJson, toPortablePath, resolvePortablePath }
+module.exports = { RESOURCES, APP_ROOT, BUILD, FILES, DATA, DIRS, ensureDirs, syncBundledTranslations, launcherIconPath, readJson, writeJson, toPortablePath, resolvePortablePath }