The reserve replay search now auto-includes waiting-list candidates when users opt into --try-waiting, so the stable train_id chosen from search remains resolvable for docs-following flows. A regression test reproduces the prior stale-train failure and locks the corrected behavior.\n\nConstraint: Reserve must keep using the existing train_id replay flow without broad CLI redesign\nRejected: Require users to repeat --include-waiting-list on reserve | contradicts the documented flow and review feedback\nConfidence: high\nScope-risk: narrow\nReversibility: clean\nDirective: Keep --try-waiting and reserve replay search semantics aligned so waiting-list-only trains remain selectable\nTested: python3 -m py_compile scripts/ktx_booking.py; python3 -m unittest discover -s scripts -p test_ktx_booking.py; node --test scripts/skill-docs.test.js; npm run ci; python3 scripts/ktx_booking.py --help; python3 scripts/ktx_booking.py reserve --help; live search/reservations/reserve/cancel/reservations via sops-managed Korail credentials\nNot-tested: Live waiting-list reservation creation (no waiting-list-eligible train appeared in the smoke search output)
Reserve used to replay search results and trust a fresh ordinal index, which could silently target a different train when sold-out entries disappeared or ordering changed. This change emits a stable train_id from search output, requires reserve to match the exact train identity on replay, and updates docs/tests to lock the safer CLI contract.
Constraint: Korail search results can reorder between search and reserve while the helper still needs to replay the live lookup
Rejected: Keep --train-index as the reserve selector | still allows silent wrong-train bookings when the result set shifts
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: If upstream train identity fields change, update the train_id payload and the docs/tests together before changing reserve selection again
Tested: python3 -m py_compile scripts/ktx_booking.py; python3 -m unittest discover -s scripts -p test_ktx_booking.py; node --test scripts/skill-docs.test.js; npm run ci; live search/reservations/reserve/cancel/reservations with sops-managed Korail credentials
Not-tested: Forced live stale-train_id failure against a disappearing train between search and reserve
Jeffrey (Dongkyu) Kim