Project rail composition and readiness

docs/rail-rapp-reef-adaptation.md

@@ -83,6 +83,16 @@ The registry now also retains the local checkout `path` used during onboarding.
 That lets Fabric reopen the conventional repo-local `rail`, `rapp`, and `reef`
 files when it needs to project first-wave relation edges.
 
+Second-wave projection also retains:
+
+- rail contract version and base/derived composition kind
+- a derived rail's `base_rail` and compatible base contract
+- rail and package readiness state
+- binding readiness, contract version, and evidence references
+
+Topology remains distinct from readiness. A relation can be declared without
+being installed, verified, or production-approved.
+
 ## First New Capability Type
 
 Fabric now reserves:
@@ -111,6 +121,7 @@ repo-local files:
   declaration
 - `binds_rapp` from `bindings/rapps.yaml` with a fallback to the reef
   declaration
+- `base_rail` from a derived rail declaration
 
 This keeps the relation path anchored in reviewed repo-local files rather than
 guessing solely from registry metadata.