test(adapters): align agy exit-key expectation with /exit

4d444ce changed the agy adapter's exit_key to /exit for a clean graceful
shutdown but left test_cli_bridge_subcommands_and_quote_safety expecting the
old 'Exit', so the full suite has failed on that one case since.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

tests/test_a4_adapter_contract.py

@@ -512,7 +512,7 @@ def test_cli_bridge_subcommands_and_quote_safety():
     assert res.stdout.strip() == "/bin/claude --dangerously-skip-permissions --session-id uuid-test"
 
     # 3. exit-key
-    for agent, expected_key in [('claude', '/exit'), ('agy', 'Exit'), ('hermes', '/exit'), ('grok', '/exit'), ('opencode', '/exit'), ('codex', 'Ctrl+C')]:
+    for agent, expected_key in [('claude', '/exit'), ('agy', '/exit'), ('hermes', '/exit'), ('grok', '/exit'), ('opencode', '/exit'), ('codex', 'Ctrl+C')]:
         res = subprocess.run([sys.executable, "-m", "lib_py.agents", "exit-key", agent], capture_output=True, text=True, env=env)
         assert res.returncode == 0
         assert res.stdout.strip() == expected_key