Add timing observation support for QWS

[yoshifuminakamura]

Summary

• add optional timing_observations result handoff for detailed timer/profiler artifacts, with result scoping for multi-result jobs
• register QWS timing tables and QWS_TIMER_SCHEMA_* markers as timing observations instead of SECTION/OVERLAP projections
• show timing observations on the authenticated result detail page only; public detail and reuse downloads stay unchanged

Validation

• bash scripts/tests/test_bk_timing_observations.sh
• bash scripts/tests/test_qws_timing_artifact.sh
• bash scripts/tests/test_result_common_json_contract.sh
• .venv/bin/python result_server/tests/run_result_server_tests.py result_server/tests/test_result_detail_template.py
• shellcheck -S error scripts/bk_functions.sh scripts/result.sh programs/qws/parse_timing.sh programs/qws/run.sh scripts/tests/test_bk_timing_observations.sh scripts/tests/test_qws_timing_artifact.sh scripts/tests/test_result_common_json_contract.sh
• shellcheck -S warning programs/qws/parse_timing.sh programs/qws/run.sh scripts/tests/test_bk_timing_observations.sh scripts/tests/test_qws_timing_artifact.sh
• python3 scripts/tests/check_text_integrity.py
• python3 scripts/tests/check_app_contracts.py
• all shell tests under scripts/tests/*.sh