Coordinate authoritative rule ownership and semantic-drift policy with philoserf/traveller

[philoserf]

Context

philoserf/traveller and philoserf/t5 implement many of the same Traveller5 mechanics but serve different product goals: a public library/API and a module-internal CLI toolkit.

The main proposal is tracked in philoserf/traveller#178. This issue makes that decision visible to t5 contributors and provides the sibling-repository coordination point.

Scope

Participate in and reflect the decision covering:

• Which repository is authoritative for each overlapping rules domain.
• How applicable fixes and rule interpretations propagate between repositories.
• Which shared seeds or worked examples should detect unintended semantic drift.
• How intentional divergences are documented and tested.
• Whether any code, verified tables, or fixtures should eventually be shared.

Acceptance criteria

• The resulting ADR or policy is linked from both repositories.
• t5 contributor documentation explains how to cross-reference overlapping changes.
• Expected equivalences and intentional differences are named.
• A small shared comparison corpus exists where semantics should match.
• This issue is closed in coordination with philoserf/traveller#178.