GAP-3: package config definitions carry no lifecycle/cache-policy/sensitivity metadata (D0.1b blocking gap)

[alexeygrigorev]

Blocking gap for D0.1c, found by the D0.1b inventory. Site declarations carry lifecycle, cache_policy (stamped) and sensitivity columns plus a docs_reference path; the package Definition has only docs_url. D0.1c either persists this metadata site-side in the adapter or drops it deliberately per column. Low urgency: no runtime reader depends on the columns today. Evidence: _docs/adoption/settings-contract-inventory.md GAP-3.