fix(interactive-subagents): avoid Orca polling fan-out

extensions/interactive-subagents/pi-extension/subagents/orca.ts

@@ -14,6 +14,7 @@ const execFileAsync = promisify(execFile);
 
 /** GNOME screen reader path — never a valid Orca CLI. */
 const GNOME_SCREEN_READER = "/usr/bin/orca";
+const ASYNC_READ_SCREEN_TIMEOUT_MS = 5_000;
 
 let cachedCli: string | null | undefined;
 
@@ -275,14 +276,26 @@ export function readScreen(surface: string, lines = 50): string {
   return parseReadTail(output);
 }
 
-export async function readScreenAsync(surface: string, lines = 50): Promise<string> {
-  const cli = requireOrca();
+async function readScreenWithCli(
+  cli: string,
+  surface: string,
+  lines: number,
+  timeout = ASYNC_READ_SCREEN_TIMEOUT_MS,
+): Promise<string> {
   const { stdout } = await execFileAsync(cli, readScreenArgs(surface, lines), {
     encoding: "utf8",
+    timeout,
+    killSignal: "SIGKILL",
   });
   return parseReadTail(stdout);
 }
 
+export async function readScreenAsync(surface: string, lines = 50): Promise<string> {
+  return readScreenWithCli(requireOrca(), surface, lines);
+}
+
+export const __orcaTest__ = { readScreenWithCli };
+
 export function closeSurface(surface: string): void {
   const cli = requireOrca();
   const args = ["terminal", "close", "--terminal", surface];