Adds 5 test cases + 3 fixtures to test_a2a_response.py covering the
push-mode queue handling added in PR #278 (a2a_proxy.go):
Fixtures:
- push_queued_full: {queued: True, method: tasks/send, message, queue_id}
- push_queued_no_method: {queued: True, message} → defaults to message/send
- push_queued_message_only: {queued: True, message} → still Queued
Test cases (TestQueuedVariant_PushMode):
- test_push_queued_full_returns_Queued
- test_push_queued_no_method_defaults_to_message_send
- test_push_queued_message_only_returns_Queued
- test_push_queued_logs_info_with_queue_id
- test_push_queued_delivery_mode_defaults_to_poll
Also updates test_every_fixture_classifies_to_expected_variant to
enumerate the 3 new fixtures so future additions must update the table.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
