Implementa o MVP do Adaptador de Planilhas no Elo Pro.

O módulo usa a identidade Supabase, isola cada workspace e registra storage, TTL, runner e biblioteca XLSX como decisões ainda abertas.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/domain/spreadsheet-adapter/preview.ts

@@ -0,0 +1,28 @@
+import { PREVIEW_ROWS } from "./limits";
+import { transformRows } from "./transform";
+import type { ColumnSchema, MappingInput } from "./types";
+
+export type PreviewContract = {
+  preview: true;
+  columns: { name: string; required: boolean }[];
+  rows: string[][];
+  rowCount: number;
+  truncated: boolean;
+};
+
+export function buildPreview(
+  modelColumns: ColumnSchema[],
+  sourceHeaders: string[],
+  dataRows: string[][],
+  mappings: MappingInput[],
+): PreviewContract {
+  const ordered = modelColumns.map((column) => column.name);
+  const all = transformRows(ordered, sourceHeaders, dataRows, mappings);
+  return {
+    preview: true,
+    columns: modelColumns.map((column) => ({ name: column.name, required: column.required })),
+    rows: all.slice(0, PREVIEW_ROWS),
+    rowCount: all.length,
+    truncated: all.length > PREVIEW_ROWS,
+  };
+}