fix(background-agent): bound session abort waits

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/features/background-agent/abort-with-timeout.ts

@@ -0,0 +1,35 @@
+import { log } from "../../shared"
+import type { OpencodeClient } from "./opencode-client"
+
+export async function abortWithTimeout(
+  client: OpencodeClient,
+  sessionID: string,
+  timeoutMs = 10_000,
+): Promise<boolean> {
+  let timeoutHandle: ReturnType<typeof setTimeout> | undefined
+
+  try {
+    const result = await Promise.race([
+      client.session.abort({ path: { id: sessionID } }).then(() => "aborted" as const),
+      new Promise<"timed_out">((resolve) => {
+        timeoutHandle = setTimeout(() => {
+          resolve("timed_out")
+        }, timeoutMs)
+      }),
+    ])
+
+    if (result === "timed_out") {
+      log("[background-agent] Session abort timed out; continuing cleanup:", {
+        sessionID,
+        timeoutMs,
+      })
+      return false
+    }
+
+    return true
+  } finally {
+    if (timeoutHandle) {
+      clearTimeout(timeoutHandle)
+    }
+  }
+}