test: add EdgeEnv replay warning fixtures

[hyeokjun32]

Summary

• add committed EdgeEnv runtime regression replay fixtures for candidate telemetry gaps and execution sequence inversion
• document the fixtures in the compare workflow guide and README
• add fixture contract coverage to keep the examples EdgeEnv-owned, without guard_analysis or deployment decision payloads

Tests

• python -m pytest -q tests/test_regression.py::test_committed_replay_warning_fixtures_preserve_edgeenv_owned_context tests/test_regression.py::test_cli_telemetry_replay_candidate_gap_to_regression_smoke tests/test_regression.py::test_regression_preserves_replay_sequence_order_mismatch_context
• python -m pytest -q
• git diff --check