Add Fiber lock script integration regression

[Xcodes-chain]

Summary

• add a dedicated fiber_test_lock_scripts CI job for Fiber lock script deployment regressions
• add integration coverage that checks FundingLock/CommitmentLock deployment cells and a force-settlement flow using commitment lock cells
• default Fiber prepare/workflow dispatch to v0.9.0-rc7 for this regression validation
• harden test.sh so pytest pipeline exit status and local runs without GITHUB_STEP_SUMMARY are handled correctly

Validation

• python -m black --check framework/rpc.py test_cases/fiber/devnet/lock_scripts/test_lock_script_deployment_regression.py
• python -m py_compile framework/rpc.py test_cases/fiber/devnet/lock_scripts/test_lock_script_deployment_regression.py
• python -m pytest --collect-only -q test_cases/fiber/devnet/lock_scripts
• local rc7 smoke: PYTHON="$PWD/venv/bin/python" make fiber_lock_scripts_test with fnn Fiber v0.9.0-rc7 (bc361aa 2026-07-02), result: 2 passed

Notes

• This is split from PR Add Fiber lock script integration regression #81 so the original PR can stay rolled back.
• The previous full CI run showed fiber_test_lock_scripts passed once the framework timeout issue was resolved; remaining failures were unrelated existing suites.