fix(factory): ask only operator-actionable questions

[walker-tx]

Summary

• separate public-documentation research limitations from operator-actionable decisions
• require every structured open question to pass first-connection, no-safe-hedge, and operator-answerability gates
• codify resilient handling for the five Box documentation gaps
• stop rendering non-scope open questions in failed and blocked issue comments

Verification

• GOFLAGS='-ldflags=-linkmode=external' bash factory/tests/run.sh (12/12 tests)
• mise x shellcheck@0.10.0 -- shellcheck factory/scripts/*.sh factory/tests/*.sh
• git diff --check
• independent review: no findings