feat: dual-run facade to repo-manager for task writeback

RMGR-WP-0002 Stage B: when RM_WRITEBACK/RM_RECONCILE flags are set, PATCH
/tasks and C-15 writeback call rmgr; fix_repo runs rmgr reconcile for pilots.

workplans/STATE-WP-0079-retirement-strangler.md

@@ -16,6 +16,7 @@ related:
   - SHR-INV-0001
   - RMGR-WP-0001
   - HUB-WP-0004
+state_hub_workstream_id: "749beac6-3c62-4284-aab5-9ed7fce900c2"
 ---
 
 # State Hub retirement strangler and disposition execution
@@ -27,12 +28,23 @@ Execute the **keep/move/replace/retire** dispositions from
 without adding new permanent authorities here. End state: freeze window with no
 normal traffic, then archive.
 
+## Dual-run handoff (RMGR-WP-0002)
+
+Repo Manager Stage B dual-run is available:
+
+- Flags: `RM_WRITEBACK`, `RM_RECONCILE`, `RM_PILOT_REPOS` (see `repo-manager/docs/dual-run.md`)
+- SH adapter: `api/services/repo_manager_dual_run.py` (PATCH `/tasks` + C-15 writeback + reconcile proxy)
+- Evidence: `repo-manager/docs/evidence/wp0002-completion.md`
+
+Expand pilot list here as cutover progresses; do not add new checkout mutators in State Hub.
+
 ## Freeze policy for new scope
 
 ```task
 id: STATE-WP-0079-T01
 status: todo
 priority: high
+state_hub_task_id: "375c0b66-98b0-4d5b-98dd-4ad2883a4051"
 ```
 
 Document and enforce: changes during retirement must preserve compatibility,
@@ -45,6 +57,7 @@ permanent ownership (INTENT retirement status).
 id: STATE-WP-0079-T02
 status: todo
 priority: high
+state_hub_task_id: "595c3936-20b6-453f-92b5-84f86798054a"
 ```
 
 Group SHR-INV-0001 items into cutover slices (repo/work → repo-manager;
@@ -57,6 +70,7 @@ Per slice: adapter flag, owner API, rollback.
 id: STATE-WP-0079-T03
 status: todo
 priority: medium
+state_hub_task_id: "55716f12-fb12-4a1e-a770-076c490db111"
 ```
 
 Adapt `statehub register` / scaffolding so `prj-` repos with `GOAL.md` and
@@ -69,6 +83,7 @@ Adapt `statehub register` / scaffolding so `prj-` repos with `GOAL.md` and
 id: STATE-WP-0079-T04
 status: todo
 priority: high
+state_hub_task_id: "db5291f2-3801-40fa-abf2-ceb0e77687c9"
 ```
 
 Implement strangler handoffs coordinated with RMGR-WP-0001 and HUB-WP-0004.
@@ -80,6 +95,7 @@ Compatibility tests for each dispositioned route family.
 id: STATE-WP-0079-T05
 status: todo
 priority: medium
+state_hub_task_id: "02e508ed-3cde-4487-907e-d324a8a877d6"
 ```
 
 Complete retirement of suggestions, workstream aliases, and other `retire`
@@ -91,6 +107,7 @@ inventory items once meters/callers allow. Keep historical rows archive-readable
 id: STATE-WP-0079-T06
 status: todo
 priority: high
+state_hub_task_id: "d52c95c6-af3f-4b2c-804e-e07763c9a8ab"
 ```
 
 With T06 gates: zero normal read/write window, final dump, backup/restore