fix(targets): harden adapter lifecycle and droid model edge cases

src/utils/shell-executor.ts

@@ -7,7 +7,7 @@
 import { spawn, spawnSync, ChildProcess } from 'child_process';
 import { ErrorManager } from './error-manager';
 import { getWebSearchHookEnv } from './websearch-manager';
-import { forwardSignals } from './signal-forwarder';
+import { wireChildProcessSignals } from './signal-forwarder';
 
 /**
  * Strip ANTHROPIC_* env vars from an environment object.
@@ -128,16 +128,7 @@ export function execClaude(
     });
   }
 
-  const cleanupSignalHandlers = forwardSignals(child);
-
-  child.on('exit', (code, signal) => {
-    cleanupSignalHandlers();
-    if (signal) process.kill(process.pid, signal as NodeJS.Signals);
-    else process.exit(code || 0);
-  });
-
-  child.on('error', async (err: NodeJS.ErrnoException) => {
-    cleanupSignalHandlers();
+  wireChildProcessSignals(child, async (err: NodeJS.ErrnoException) => {
     if (err.code === 'EACCES') {
       console.error(`[X] Claude CLI is not executable: ${claudeCli}`);
       console.error('    Check file permissions and executable bit.');

src/utils/signal-forwarder.ts

@@ -31,3 +31,47 @@ export function forwardSignals(child: ChildProcess): () => void {
     process.removeListener('SIGHUP', forwardSighup);
   };
 }
+
+export type ChildProcessErrorHandler = (err: NodeJS.ErrnoException) => void | Promise<void>;
+export type ChildProcessExitHandler = (code: number | null, signal: NodeJS.Signals | null) => void;
+
+function defaultExitHandler(code: number | null, signal: NodeJS.Signals | null): void {
+  if (signal) process.kill(process.pid, signal);
+  else process.exit(code || 0);
+}
+
+/**
+ * Attach shared signal-forwarding lifecycle handlers to a child process.
+ * Ensures signal listeners are always cleaned up on child exit/error.
+ */
+export function wireChildProcessSignals(
+  child: ChildProcess,
+  onError: ChildProcessErrorHandler,
+  onExit: ChildProcessExitHandler = defaultExitHandler
+): void {
+  const cleanupSignalHandlers = forwardSignals(child);
+  let settled = false;
+
+  const settle = (): boolean => {
+    if (settled) return false;
+    settled = true;
+    cleanupSignalHandlers();
+    return true;
+  };
+
+  child.on('exit', (code, signal) => {
+    if (!settle()) return;
+    onExit(code, signal);
+  });
+
+  child.on('error', async (err: NodeJS.ErrnoException) => {
+    if (!settle()) return;
+    try {
+      await onError(err);
+    } catch (handlerErr) {
+      const message = handlerErr instanceof Error ? handlerErr.message : String(handlerErr);
+      console.error(`[X] Failed to handle child process error: ${message}`);
+      process.exit(1);
+    }
+  });
+}