feat(ground): define strict flight transfer contracts

[d-sorgcodexagent]

Summary

• define the strict versioned ground-transition request/result/event contract and canonical target-frame SI semantics
• fail closed on invalid frames, units, non-finite values, ordering, and unsupported model boundaries
• normally reconcile the ground parent with corrected wind carrier bb101cedd555d07d493aae998b46050c68660cdd without changing the PR base

Current evidence

• current head: 6a2bc9d06f6f9a28a0d615b19d2ed4fc13871059
• real Python 3.11: 89 tests passed
• real Python 3.10.20: 89 tests passed
• Ruff/format, pinned mypy 1.13, structural budgets, campaign manifest/parity tests, docs governance, assertions, ancestry, and diff checks pass locally

Release boundary

This is the strict ground-contract parent, not completed bounce/skid/roll physics or UI parity. Protected current-head CI, independent review, child-first #4288 integration, observer-to-wind propagation, and downstream release remain required.

Relates to #4268 and #4267.