docs: finish financial fabric reset guidance

docs/registry-api.md

@@ -1,7 +1,10 @@
 # Registry API
 
-The Railiance Fabric registry is a small HTTP API over repo-owned Fabric
-declarations and supporting inventory.
+The Railiance Fabric registry is a small HTTP API over accepted Fabric graph
+snapshots, discovery evidence, reset archives, and supporting inventory.
+Legacy repo-local declarations can still produce snapshots, but they are
+evidence for the graph rather than the long-term authority for external
+deployment, ownership, tenant, or utility relations.
 
 ## Health And Status
 
@@ -27,7 +30,9 @@ GET  /repositories/{repo_slug}/snapshots/diff
 ```
 
 Snapshot ingestion accepts a `FabricGraphExport` under `graph` plus `commit`
-and optional `generated_at`.
+and optional `generated_at`. The registry accepts both legacy
+`railiance.fabric/v1alpha1` graph exports and the financial
+`railiance.fabric/v1alpha2` / `financial-fabric-v1` export contract.
 
 ## Discovery Snapshots
 
@@ -102,6 +107,12 @@ GET /exports/graph-explorer
 GET /exports/reset-archive
 ```
 
+`GET /exports/state-hub` currently serves the accepted combined graph for the
+State Hub read model. During the financial reset, keep using the legacy shape
+for existing State Hub views until `STATE-WP-0051` materializes v1alpha2
+fields. Use `railiance-fabric export --format financial` and
+`examples/exports/financial-fabric-v1.json` as the vNext contract references.
+
 ## Guarded Reset
 
 ```text