Create protected board defaults

docs/circuit-list-editor-api.md

@@ -194,11 +194,14 @@ returns HTTP `409` with `PROJECT_HISTORY_OPERATION_UNAVAILABLE`.
   - `supplyType` is one of `AV`, `SV`, `EV`, `USV`, `MSR` or `SiBe` and must
     be enabled in the project settings
   - executes `distribution-board.insert` with stable ids for the distribution
-    board, its circuit list and all four default circuit sections
+    board, its circuit list, the three default circuit groups, main switch
+    `-Q0` and surge protective device `-FA`
   - response:
     `{ "distributionBoard": { ... }, "revision": { ... }, "history": { ... } }`
   - persistent Undo removes only the unchanged and still-empty generated
     structure; Redo restores the same ids
+  - stored command schema versions 1 and 2 remain executable with their four
+    legacy sections and without generated components
   - stale revisions return `409 PROJECT_REVISION_CONFLICT`
 - `PUT /projects/:projectId/distribution-boards/:distributionBoardId`
   - body: