feat: improve NodeCG runtime installation and relaunch behavior

src/main/nodecg/process-manager.ts

@@ -80,7 +80,8 @@ export function createNodecgProcessManager({
       },
       stdio: ["ignore", "pipe", "pipe"],
       detached: resolvedDeps.platform !== "win32",
-      shell: resolvedDeps.platform === "win32",
+      shell: false,
+      windowsHide: true,
     });
 
     child.stdout?.on("data", (chunk) => {
@@ -163,7 +164,15 @@ export function createNodecgProcessManager({
     killNodecgProcessTree(pid, "SIGTERM", log, resolvedDeps);
 
     stopNodecgPromise = new Promise((resolve) => {
+      let completed = false;
+
       const complete = () => {
+        if (completed) {
+          return;
+        }
+
+        completed = true;
+
         if (nodecgProcess === processToStop) {
           nodecgProcess = null;
         }
@@ -181,6 +190,7 @@ export function createNodecgProcessManager({
           if (processToStop.exitCode === null && processToStop.signalCode === null) {
             log(`NodeCG did not exit after SIGTERM, forcing SIGKILL pid=${pid}`);
             killNodecgProcessTree(pid, "SIGKILL", log, resolvedDeps);
+            complete();
           }
         },
         Math.max(0, appConfig.nodecgKillTimeoutMs),