fix: stop orphaned opencode processes on desktop quit

Exit the desktop app without waiting on background cleanup
Kill managed OpenCode by process group with a port fallback
Make OpenCode shutdown reuse the active shutdown promise

packages/web/server/lib/opencode/lifecycle.js

@@ -152,6 +152,20 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
       return;
     }
 
+    const signalProcessTree = (signal) => {
+      if (process.platform !== 'win32') {
+        try {
+          process.kill(-pid, signal);
+        } catch {
+        }
+      }
+
+      try {
+        child.kill(signal);
+      } catch {
+      }
+    };
+
     if (process.platform === 'win32') {
       try {
         child.kill();
@@ -188,19 +202,13 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
       return;
     }
 
-    try {
-      child.kill('SIGTERM');
-    } catch {
-    }
+    signalProcessTree('SIGTERM');
 
     if (await waitForChildProcessClose(child, 2500)) {
       return;
     }
 
-    try {
-      child.kill('SIGKILL');
-    } catch {
-    }
+    signalProcessTree('SIGKILL');
 
     await waitForChildProcessClose(child, 1000);
   };
@@ -274,6 +282,7 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
     const child = spawn(binary, args, {
       cwd,
       env: processEnv,
+      detached: process.platform !== 'win32',
       windowsHide: true,
       stdio: ['ignore', 'pipe', 'pipe'],
     });
@@ -336,6 +345,7 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
 
     return {
       url,
+      pid: child.pid || null,
       async close() {
         await closeManagedOpenCodeChild(child);
       },

packages/web/server/lib/opencode/shutdown-runtime.js

@@ -29,7 +29,9 @@ export const createGracefulShutdownRuntime = (dependencies) => {
     tunnelAuthController,
   } = dependencies;
 
-  const gracefulShutdown = async (options = {}) => {
+  let shutdownPromise = null;
+
+  const runShutdown = async (options = {}) => {
     if (getIsShuttingDown()) return;
 
     setIsShuttingDown(true);
@@ -133,6 +135,12 @@ export const createGracefulShutdownRuntime = (dependencies) => {
     }
   };
 
+  const gracefulShutdown = (options = {}) => {
+    if (shutdownPromise) return shutdownPromise;
+    shutdownPromise = runShutdown(options);
+    return shutdownPromise;
+  };
+
   return {
     gracefulShutdown,
   };