feat(CORE-001D1): harden unit-aware workspace persistence

docs/CORE-001D_BOUNDARY_CLEANUP_PLAN.md

@@ -108,9 +108,6 @@ Deliverables:
 - replacing every float in every Pydantic/dataclass immediately
 - redesigning third-party payload models wholesale
 - changing public UI formatting behavior just for type purity
-- solving instrument-level share-to-underlying conversion semantics such as `GLD share = 0.1 ozt` inside this slice alone
-
-That broader instrument-aware unit problem is tracked separately in `CORE-002`.
 
 ## First candidate sub-slices
 
@@ -130,3 +127,13 @@ That broader instrument-aware unit problem is tracked separately in `CORE-002`.
 - Decimal/unit-safe values cross boundaries through named adapters
 - remaining float-heavy hotspots are either removed or intentionally documented as edge-only
 - no regression in existing browser-visible flows
+
+## Pre-launch rollout policy
+For the current pre-launch stage, the storage schema may make a clean breaking transition.
+
+That means:
+- newly persisted numeric domain values should use explicit structured unit-aware storage
+- old flat storage payloads do not need compatibility or migration yet
+- invalid or old-format payloads should fail loudly instead of being silently normalized
+
+A real migration path should be introduced later, once persistence is considered live for users.