fix(desktop): hard-exit a lock-losing second instance before ready

app.quit() does not stop a lock-losing instance from reaching whenReady:
the before-quit teardown coordinator defers the quit (event.preventDefault
+ async backend shutdown), and ready fires in that window. The losing
instance then runs the full startup whose reapOrphans() SIGTERMs the
running instance's live backend (#87295).

The lock-loser holds no state and no backend — requestSingleInstanceLock()
has already delivered the argv to the primary by the time it returns false —
so there is nothing to clean up. app.exit(0) terminates immediately, before
ready, so a second launch routes into the running window and never touches
backend machinery.

apps/desktop/electron/main.ts

@@ -14105,9 +14105,17 @@ function registerDeepLinkProtocol() {
 // second-instance argv. Without the lock a second `hermes://` launch spawns a
 // whole new app instead of routing into the running one.
 const _gotSingleInstanceLock = app.requestSingleInstanceLock()
+const isPrimaryInstance = _gotSingleInstanceLock
 
-if (!_gotSingleInstanceLock) {
-  app.quit()
+if (!isPrimaryInstance) {
+  // Hard-exit, not app.quit(): the before-quit teardown coordinator defers a
+  // plain quit (event.preventDefault + async backend shutdown), and in that
+  // window `ready` still fires — the lock-losing instance then runs the full
+  // startup (shortcut registration, createWindow → startHermes), whose
+  // reapOrphans() SIGTERMs the running instance's live backend (#87295).
+  // app.exit() terminates immediately, before `ready`, so a second launch
+  // routes into the running window and never touches backend machinery.
+  app.exit(0)
 } else {
   app.on('second-instance', (_event, argv) => {
     const url = _extractDeepLink(argv)