Persist circuit group renumbering

docs/spec/08-current-product-backlog.md

@@ -26,7 +26,7 @@ requirements and intended sequencing, not proof of implementation.
 - [x] Phase C2b1: empty-group insert/update/delete commands.
 - [x] Phase C2b2: complete group reorder command.
 - [x] Phase D1a: deterministic collision-aware group-renumber plan.
-- [ ] Phase D1b: persistent collision-safe group-renumber command.
+- [x] Phase D1b: persistent collision-safe group-renumber command.
 - [ ] Phase D2: same-category cross-group circuit moves.
 - [ ] Phase D3: confirmed populated-group deletion.
 - [ ] Phase E: editor projection and editing.

docs/spec/09-distribution-board-components-and-protection-groups.md

@@ -662,9 +662,8 @@ Acceptance:
 
 ### D. Group Numbering and Circuit Moves
 
-Status: In progress. The deterministic renumber planner D1a is complete;
-persistent execution D1b, cross-group moves D2 and populated deletion D3
-remain pending.
+Status: In progress. Deterministic planning D1a and persistent execution D1b
+are complete; cross-group moves D2 and populated deletion D3 remain pending.
 
 - implement nested identifier generation
 - support same-category cross-group circuit moves
@@ -680,6 +679,17 @@ Implemented in D1a:
 - collisions with unchanged groups, no-op mappings and mismatched current BMKs
   are rejected before persistence
 
+Implemented in D1b:
+
+- `circuit-group.renumber` persists the complete expected/target plan as one
+  project revision
+- group-number swaps use collision-safe temporary group identities and BMKs
+  across both circuit and component tables
+- every current circuit and group component must be included unchanged before
+  execution starts
+- Undo/Redo uses the exact inverse plan; late revision/history failures roll
+  back every group, prefix and BMK
+
 Acceptance:
 
 - target identifiers use highest suffix plus one