feat: add return to service workflow

docs/releases/v0.2-repair-workflow.md

@@ -15,10 +15,10 @@ and immutable history.
 
 - [x] Begin Repair (`POST /api/repairs`)
 - [x] Repair detail and timeline read APIs
+- [x] Return to Service (`POST /api/repairs/{repair_id}/complete`)
 
 ## Planned
 
-- [ ] Return to Service
 - [ ] Control Board Replacement
 - [ ] Repair Parts Tracking
 
@@ -41,9 +41,8 @@ not make these workflows complete.
 
 ## Candidate Task Order
 
-1. `003-return-to-service.md`
-2. `004-control-board-replacement.md`
-3. `005-repair-parts-tracking.md`
+1. `004-control-board-replacement.md`
+2. `005-repair-parts-tracking.md`
 
 These are proposed future files under `docs/tasks/`. They do not exist yet and
 must not be treated as approved specifications until they are created and