feat: serve plugin http and websockets from one mount instead of ports

electron/main.cjs

@@ -1024,8 +1024,8 @@ function getBackendPidFilePath() {
 // Manager) rather than through the normal quit flow, will-quit never fires
 // and stopBackendServer() never runs -- the forked backend child is a
 // genuinely separate OS process on Windows/mac/Linux, so it keeps running
-// and holding every port the backend binds (30001, 30003-30008, 30010,
-// 30012...). Every subsequent launch's own backend then fails outright
+// and holding every port the backend binds (30001, 30003, 30004, 30006,
+// 30010-30012). Every subsequent launch's own backend then fails outright
 // with EADDRINUSE and the app is stuck until something manually kills the
 // orphan. Reap any such leftover process, identified by PID file, before
 // spawning a new one.