docs(workplans): RMGR-WP-0004-T09 assign ownership of shared prefixes

Three prefixes across seven repos, each a concurrently-allocated number
line. Recommends the-custodian keeps CUST-WP-, RAIL-BS- needs a call, and
RAILIANCE- is retired outright since it names a family rather than a repo —
the same defect as PRJ-WP-. Execution of each rename belongs to a worker in
that repo per ADR-007 decision 4.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

workplans/RMGR-WP-0004-repository-standards-conformance.md

@@ -233,6 +233,48 @@ Detection only. Remediating the existing collisions is an open ruling in
 **This task gates `RMGR-WP-0005`.** Deterministic identifier derivation from a
 non-unique identifier would manufacture UUID collisions rather than remove them.
 
+## Assign ownership of the shared prefixes
+
+```task
+id: RMGR-WP-0004-T09
+status: wait
+priority: high
+```
+
+Three prefixes are shared across seven repositories, each a single number line
+allocated from concurrently. Under `ADR-007` decision 1 each must resolve to one
+owning repository **before the next workplan is created** in the affected repos.
+
+This is forward conformance, not migration: `ADR-007` § Migration ruled option 2,
+so historical files keep their identifiers and are not renamed.
+
+| Prefix | Current holders | State |
+|---|---|---|
+| `CUST-WP-` | the-custodian (50), state-hub (4 legacy) | dormant on the state-hub side |
+| `RAIL-BS-WP-` | railiance-cluster (6), railiance-bootstrap (2) | **growing** — `RAIL-BS-WP-0014` ready |
+| `RAILIANCE-WP-` | railiance-platform (12), apps (2), forge (1), telemetry (1) | **growing** — forge `0002` ready, telemetry `0001` proposed |
+
+Recommended assignments, to be confirmed with each owning repo:
+
+- `CUST-WP-` → `the-custodian`. `state-hub`'s canonical prefix is already
+  `STATE-WP` (`C-26` says so today); its four legacy files stay as history.
+- `RAIL-BS-WP-` → needs a call. The name reads as *railiance-bootstrap*, but
+  `railiance-cluster` holds more plans and is the active user. Whichever repo
+  does not keep it takes a new prefix from its own identity.
+- `RAILIANCE-WP-` → recommend **none of them keep it**. `RAILIANCE` names a
+  family, not a repository, so it fails decision 1's requirement that prefixes
+  derive from project or repository identity — the same defect as `PRJ-WP-`.
+  Give each of the four repos a prefix from its own name.
+
+Per `ADR-007` decision 4, the rename of a repository's own convention is
+executed by a worker in that repository. This task assigns and records
+ownership in the registry (T08) and coordinates; it does not reach in and
+rewrite those repos.
+
+`RAILIANCE-WP-0015`'s ambiguity between `railiance-apps` and
+`railiance-platform` persists by design under option 2. Note it in the registry
+so citations are forced to name the repository.
+
 ## Confirm the canon boundary
 
 ```task