Add overlay runtime import for packed events

docs/README.md

@@ -67,17 +67,18 @@ Current local tool status:
 The atlas milestone is broad enough that the next implementation focus has already shifted downward
 into runtime rehosting. The current runtime baseline now includes deterministic stepping, periodic
 trigger dispatch, normalized runtime effects, staged event-record mutation, fixture execution,
-state-diff tooling, tracked save-slice documents for captured-runtime inputs, and a packed-event
-persistence bridge that now reaches per-record summaries and selective executable import.
+state-diff tooling, tracked save-slice documents for captured-runtime inputs, overlay import
+documents that combine captured snapshots with save-derived state, and a packed-event persistence
+bridge that now reaches per-record summaries and selective executable import.
 
 The highest-value next passes are now:
 
 - preserve the atlas and function map as the source of subsystem boundaries while continuing to
   avoid shell-first implementation bets
+- use captured-context overlay imports whenever save-derived packed rows need live runtime context
+  that the save slice does not actually persist
 - widen packed-event target-family coverage only where static evidence is strong enough to support
-  deterministic executable import
-- add the next imported object/context families needed to turn current parity-only packed rows into
-  executable runtime records
+  deterministic executable import after the necessary runtime context is present
 - use `rrt-hook` primarily as optional capture or integration tooling, not as the first execution
   environment
 - keep `docs/runtime-rehost-plan.md` current as the runtime baseline and next implementation slice