[F032] test: unknown-assignee claim reaches release-to-pending path

F031's role_for_slug_or_none fix made the unknown-assignee release branch
in _dispatch_claimed_without_agent reachable (the human-only guard no
longer raises/short-circuits on a stale slug). Lock that reachability in:
a claimed task with an unknown-assignee UUID past grace returns the slug
(not None) so get_agent_role -> 'unknown' releases the claim to pending
for a role-matched reclaim.

tests/unit/runtime/test_blocker_and_claimed_dispatch.py

@@ -15,6 +15,7 @@ from __future__ import annotations
 from datetime import UTC, datetime, timedelta
 from typing import Any
 from unittest.mock import AsyncMock, MagicMock, patch
+from uuid import uuid4
 
 import pytest
 from roboco.models.runtime import AgentInstance
@@ -194,6 +195,29 @@ def test_in_progress_task_with_no_agent_returns_assignee() -> None:
     assert orch._claimed_task_needs_agent(task) == "fe-dev-2"
 
 
+def test_claimed_task_with_unknown_assignee_returns_slug_for_release() -> None:
+    # F032: a claimed/in_progress task whose assignee is a stale/unknown UUID
+    # (no seeded agent) must reach the release-to-pending path. The human-only
+    # guard (role_for_slug_or_none) returns None for an unknown slug, and
+    # ``None in (CEO, PROMPTER, SECRETARY)`` is False — so it does NOT
+    # short-circuit, the slug falls through the grace window, and the resolver
+    # returns the unknown slug. _dispatch_claimed_without_agent then sees
+    # get_agent_role(slug) == "unknown" and releases the claim to pending for
+    # a role-matched reclaim. Before F031's role_for_slug_or_none fix the guard
+    # raised KeyError on the unknown slug, crashing the whole tick before the
+    # release path could run.
+    orch = _orch()
+    unknown_uuid = str(uuid4())
+    task: dict[str, Any] = {
+        "id": "t1",
+        "status": "claimed",
+        "assigned_to": unknown_uuid,
+        "updated_at": _STALE,
+    }
+    # Returns the (unknown) slug, NOT None — the release path is reachable.
+    assert orch._claimed_task_needs_agent(task) == unknown_uuid
+
+
 # ---------------------------------------------------------------------------
 # _get_prompt_for_agent — role-appropriate respawn prompt (#19)
 # ---------------------------------------------------------------------------