Add circuit reorder history

docs/project-history-and-external-model-architecture.md

@@ -186,13 +186,16 @@ Completed foundation:
   empty target-circuit snapshot; forward creation and all row moves share one
   transaction, while undo restores the source positions and deletes only an
   unchanged generated target
+- `circuit.reorder-section` requires the complete section circuit set and
+  stores exact expected/target sort positions; its inverse changes no
+  equipment identifier and never splits a circuit block
 
 Remaining constraints before completing persistent history:
 
 - extend the concrete project-scoped command union and executors beyond the
   Circuit field/insert/delete and CircuitDeviceRow
-  field/insert/delete/move slices; the generic versioned command envelope is
-  complete
+  field/insert/delete/move plus section-reorder slices; the generic versioned
+  command envelope is complete
 - route the remaining structural, synchronization and destructive domain
   writes through the shared command, revision and stack transaction boundary
 - replace the session-local frontend command stack only after server-side