Add Revit initial import wizard

docs/circuit-list-editor-api.md

@@ -404,7 +404,17 @@ project device never triggers synchronization implicitly.
   - returns transport metadata, SHA-256, row classifications, suspect row
     numbers and mapped source values for every recognized IFC object
   - does not persist a draft, mutate project state or create a revision
+- `POST /projects/:projectId/external-csv/initial-import/plan`
+  - reparses the file and returns grouped room/family decisions plus current
+    room, distribution-board and ProjectDevice catalogs
+  - is stateless and rejects an already imported external source
+- `POST /projects/:projectId/external-csv/initial-import/apply`
+  - requires the expected revision, configuration version, file hash and one
+    decision for every room and exact family/type group
+  - reparses the file, blocks unknown family/type values and executes
+    `external-import.apply-initial` as one undoable project revision
+  - creates no Circuit or CircuitDeviceRow
 
 Parser errors expose stable codes such as `header-not-found`,
-`ambiguous-header`, `invalid-ifc-guid` and `duplicate-ifc-guid`. A later
-confirmed import must upload and parse the file again and verify its hash.
+`ambiguous-header`, `invalid-ifc-guid` and `duplicate-ifc-guid`. The confirmed
+import uploads and parses the file again and verifies its hash.