feat: model repo standards and detect prefix collisions

Implement RMGR-WP-0004 T01 (flavor, required files, anti-patterns from
canon) and T08 (prefix ownership registry plus uniqueness scan).
rmgr conform and rmgr prefix-uniqueness are detection only.

config/workplan-prefix-registry.yaml

@@ -0,0 +1,53 @@
+# RMGR-WP-0004-T08 / ADR-007 decision 1
+# One prefix, one repository. Prefixes derive from repo or project identity,
+# never from a flavor marker or family name. Detection only — historical
+# collisions stay until ADR-007 § Migration is ruled.
+
+standard: workplan-prefix-ownership
+version: "0.1"
+canon:
+  - the-custodian/canon/architecture/adr-007-workplan-identity-and-repo-worker-topology.md
+  - the-custodian/canon/standards/project-repository-flavor_v0.1.md
+
+retired:
+  - prefix: PRJ-WP
+    reason: flavor marker; never a valid prefix
+  - prefix: RAIL-BS-WP
+    reason: shared family name, not a repository
+    successors: [RCLUSTER-WP, RBS-WP]
+  - prefix: RAILIANCE-WP
+    reason: family name, not a repository
+    successors: [RPF-WP, RAPPS-WP, RFORGE-WP, RTELE-WP]
+
+owners:
+  RMGR-WP: repo-manager
+  CUST-WP: the-custodian
+  STATE-WP: state-hub
+  CFED-WP: prj-canon-federation
+  SHR-WP: prj-state-hub-retirement
+  RCLUSTER-WP: railiance-cluster
+  RBS-WP: railiance-bootstrap
+  RPF-WP: railiance-platform
+  RAPPS-WP: railiance-apps
+  RFORGE-WP: railiance-forge
+  RTELE-WP: railiance-telemetry
+  RMASTER-WP: railiance-master
+  RAIL-K8S-WP: rail-kubernetes
+  RAPP-OPENBAO-WP: rapp-openbao
+  RAPP-USER-ENGINE-WP: rapp-user-engine
+  RAPP-TENANT-ENGINE-WP: rapp-tenant-engine
+  RAPP-POLICY-NEXUS-WP: rapp-policy-nexus
+  USER-WP: user-engine
+  TEN-WP: tenant-engine
+
+historical_collisions:
+  - id: RAILIANCE-WP-0015
+    repos: [railiance-platform, railiance-apps]
+  - id: RAILIANCE-WP-0016
+    repos: [railiance-platform, railiance-apps]
+  - id: CUST-WP-0000
+    repos: [the-custodian]
+  - id: CUST-WP-0010
+    repos: [the-custodian]
+  - id: CUST-WP-0045
+    repos: [the-custodian]