Oracle/RAS execution-tier coverage for session identity hooks

R429 shipped the session identity hooks (connect/disconnect from <sessionState>, handle threading, the per-settle re-fire fallback for hooks without <stateSurvivesTransactions>) with execution-tier proof on Postgres only; Oracle stays unit-tier because the build has no Oracle container. The Oracle worked example is the load-bearing one for Sikt’s kernel API (definer-rights package, VPD institution context, RAS CREATE_SESSION/ATTACH_SESSION with the session id as the OUT handle, detach/destroy by handle on disconnect), so the two-hook contract, handle capture and rebinding, the outside-any-transaction invariant, and the re-fire fallback should each be proven against a real Oracle database once a container (or an external test target, like the test.db.url seam the Postgres tiers already use) is available. Named as a follow-on in R429’s slice 3; this item is its tracking home now that the R429 spec is deleted.