Project repo-family relations from local declarations

docs/registry-onboarding.md

@@ -51,7 +51,9 @@ repositories:
     sbom: bom.json
 ```
 
-`path` is the local checkout used for git metadata and default graph discovery.
+`path` is the local checkout used for git metadata, default graph discovery,
+and repo-family relation projection when the registry later needs to reopen
+repo-local `rail`, `rapp`, or `reef` files.
 `declaration_paths` is optional; when omitted, the repo path is scanned for a
 `fabric/` directory. Relative paths are resolved from the manifest file.
 
@@ -68,7 +70,7 @@ The following repo-family metadata fields are also optional:
   declared
 - `supported_rails`: array of supported rail ids for `rapp-*` repos
 - `substrate_kind`: grouped substrate category such as `server`,
-  `workstation-group`, or `cluster`
+  `server-group`, `workstation-group`, or `cluster`
 
 `sbom` or `sboms` may point to CycloneDX JSON/YAML files. When present, the
 command ingests them as queryable library inventory after repository
@@ -81,6 +83,12 @@ no Fabric declarations yet, the command leaves the repo registered and reports a
 warning. This lets the registry represent known repos before every repo has
 published local evidence.
 
+For `rail-*`, `rapp-*`, and `reef-*` repos, registration-only entries still
+matter: the registry stores the checkout path and repo-family metadata, and the
+graph export can use the conventional repo-local declaration files to project
+first-wave `governed_by`, `supports_rail`, `hosts_rail`, and `binds_rapp`
+edges even when the repo does not yet publish native Fabric declarations.
+
 When declarations exist, the command validates them, builds a graph snapshot,
 and posts it to: