fix(api): catch subprocess timeouts in exec_bash_command

'from redis.asyncio import ... TimeoutError' shadowed the builtin
TimeoutError. redis's TimeoutError is a RedisError subclass, not a
builtin subclass, so the 'except TimeoutError' guarding
asyncio.wait_for never matched: timed-out commands fell through to the
generic handler, the child process was never terminated (leak), and
the caller got a misleading 'unable to execute' error instead of a
timeout.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/api/utils.py

@@ -9,7 +9,9 @@ from typing import Any, Dict, Optional
 
 from fastapi.encoders import jsonable_encoder
 from loguru import logger
-from redis.asyncio import Redis, TimeoutError
+# NB: do not import redis's TimeoutError here — it would shadow the builtin
+# and asyncio.wait_for's builtin TimeoutError would never be caught below.
+from redis.asyncio import Redis
 
 from app.api.error_report.report import Report
 from app.api.models import ProcessResult

tests/test_exec_bash_timeout.py

@@ -0,0 +1,23 @@
+"""
+Regression test: exec_bash_command must actually catch the timeout raised
+by asyncio.wait_for.
+
+`from redis.asyncio import ... TimeoutError` used to shadow the builtin, so
+`except TimeoutError` never matched asyncio's builtin TimeoutError. Timed-out
+commands fell through to the generic handler, the child process was never
+terminated, and the caller got a misleading "unable to execute" error.
+"""
+
+from app.api.utils import exec_bash_command
+from app.external.result_type.src.result.result import Err
+
+
+async def test_exec_bash_command_reports_timeout():
+    # `bash -c 'sleep 5'` with a 0.5s budget must time out
+    res = await exec_bash_command("-c 'sleep 5'", timeout=0.5)
+
+    assert isinstance(res, Err), "a timed-out command must return an Err"
+    message = res.err_value.format_verbose().lower()
+    assert "timed out" in message, (
+        f"expected a timeout error, got: {message}"
+    )