Harden Linear XLSX end to end

docs/circuit-list-editor-api.md

@@ -67,8 +67,9 @@ Prüfsumme; Ersetzen übernimmt die Grobbilanzen atomar und mit Undo/Redo,
 Duplizieren vergibt neue IDs. Transferformat 1 bleibt ohne Grobbilanzen
 importierbar.
 
-Das aktuelle Projekt-Snapshot-Schema 9 enthält die logischen Einspeisungsverweise
-der Verteilungen; Versionen 1–8 werden mit leeren Verweisen hochgestuft. Schema 8
+Das aktuelle Projekt-Snapshot-Schema 10 enthält Linear-XLSX-Zustand und die in
+Schema 9 eingeführten logischen Einspeisungsverweise der Verteilungen;
+Versionen 1–8 werden mit leeren Verweisen hochgestuft. Schema 8
 enthält außerdem die optionale Netto-Raumfläche `rooms[].areaM2`.
 Snapshot-Versionen 1–7 werden dafür mit
 `areaM2 = null` hochgestuft. Restore, Export und Import erhalten vorhandene
@@ -485,40 +486,32 @@ read nor write project data; applying a result uses `circuit.update` through
 
 Full request example and calculation rules: `docs/cable-sizing-module.md`.
 
-## Revit CSV Foundation
+## Revit / Linear XLSX
 
-- `GET /projects/:projectId/external-csv/configuration`
-  - returns the complete versioned project configuration or `null`
-- `PUT /projects/:projectId/external-csv/configuration`
-  - request: `expectedRevision` and the complete validated configuration
-  - executes `external-csv-configuration.update`
-  - returns configuration, revision and project history state
-- `POST /projects/:projectId/external-csv/preview`
-  - request: file name and Base64-encoded CSV content up to 18 MB
-  - requires a stored project configuration
-  - 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
-- `GET /projects/:projectId/circuit-lists/:circuitListId/external-objects`
-  - resolves the circuit list's distribution board server-side
-  - returns only external objects assigned to that board, with unassigned
-    objects first, their source room/marker values and current row-link status
-  - returns an empty list when the optional Revit import does not exist
-  - is read-only and exposes no stored command payloads or import bytes
+- `GET|PUT /projects/:projectId/external-model/configuration` reads or writes
+  the complete XLSX configuration. PUT requires `expectedRevision`.
+- `POST /projects/:projectId/external-model/configuration/detect` detects the
+  sheet layout and columns from an uploaded `.xlsx` sample without persisting.
+- `GET /projects/:projectId/external-model/import-status` returns the latest
+  batch metadata, object count and current missing-object count.
+- `POST .../initial-import/plan|apply` provides the stateless initial plan and
+  its confirmed atomic application. Apply retransmits and reparses the XLSX.
+- `POST .../follow-up-import/plan|apply` classifies exact Worksharing-ID
+  additions, source changes, unchanged and missing objects. Apply requires the
+  preview hash and source decisions and updates linked row quantities atomically.
+- `GET|PUT .../external-model/objects` loads one compact project list and
+  applies revision-safe multi-object planning changes.
+- `POST .../objects/assign-row|assign-new-row|assign-new-circuit|detach-row`
+  changes external-object row assignments through persistent commands.
+- `POST .../objects/delete-missing` requires `confirmed: true`, deletes only
+  objects marked missing and adjusts linked row quantities in the same command.
+- `POST .../external-model/return-workbook` creates the structure-preserving
+  return XLSX for all, deviating or selected objects.
+- `GET .../external-model/export-batches` returns append-only export metadata.
 
-Parser errors expose stable codes such as `header-not-found`,
-`ambiguous-header`, `invalid-ifc-guid` and `duplicate-ifc-guid`. The confirmed
-import uploads and parses the file again and verifies its hash.
+Uploads accept only `.xlsx` up to 10 MiB. Worksharing-IDs are exact and
+case-sensitive; IfcGUID is optional and non-unique. Undo/Redo uses persisted
+command states and never reparses workbook bytes.
 
 ## Document Branding (print view)