feat: add brief concept party classification

src/boardDomain.ts

@@ -79,6 +79,7 @@ export function normalizeCase(state: CaseState): CaseState {
   const normalized = { ...state, relations }
   return {
     ...normalized,
+    brief: state.brief || { body: '', concepts: [] },
     documents: state.documents.map(document => ({
       ...document,
       fileType: document.fileType || (document.mimeType?.startsWith('image/') ? 'image' : document.mimeType === 'application/pdf' ? 'pdf' : 'file'),