Reduces setup_env_for_cloud (84 lines -> 8 lines) and assert_cloud_api_calls
(32 lines -> 9 lines) in test/mock.sh by moving cloud-specific data into
per-cloud _env.sh and _api_assertions.sh files in test/fixtures/.
Adding a new cloud's test config now only requires creating two small files
in the fixtures directory instead of editing case branches in mock.sh.
Agent: complexity-hunter
Co-authored-by: A <6723574+louisgv@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
