e00f461eb1
The test 'hephaestus is created when github-copilot provider is connected' had incorrect expectation. github-copilot does not provide gpt-5.3-codex, so hephaestus should NOT be created when only github-copilot is connected. This test was causing CI flakiness due to incorrect assertion and missing readConnectedProvidersCache mock (state pollution between tests). Also adds cacheSpy mock for proper isolation.