feat: add book transcripts categorisation

lib/transcriptions.ts

@@ -59,6 +59,12 @@ export type PlaceGroup = {
   count: number;
 };
 
+export type BookGroup = {
+  code: string;
+  title: string;
+  count: number;
+};
+
 // ---------------------------------------------------------------------------
 // BFF response types (snake_case from Go)
 // ---------------------------------------------------------------------------
@@ -185,6 +191,16 @@ export async function getTranscriptionPlaces(): Promise<PlaceGroup[]> {
     .sort((a, b) => b.count - a.count);
 }
 
+export async function getTranscriptionBooks(): Promise<BookGroup[]> {
+  const raw = await bffList<{ _id: string; title: string; count: number }>(
+    "/transcriptions/books",
+    { tags: ["transcriptions"] },
+  );
+  return raw
+    .map((item) => ({ code: item._id, title: item.title, count: item.count }))
+    .sort((a, b) => b.count - a.count);
+}
+
 export async function getTotalTranscriptionCount(): Promise<number> {
   const res = await bff<{ count: number }>("/transcriptions", {
     tags: ["transcriptions"],
@@ -248,6 +264,16 @@ export async function getTranscriptionsByType(
   return raw.map(mapSummary);
 }
 
+export async function getTranscriptionsByBook(
+  code: string,
+): Promise<TranscriptionSummary[]> {
+  const raw = await bffList<BffSummary>(
+    `/transcriptions/book/${encodeURIComponent(code)}`,
+    { tags: ["transcriptions"] },
+  );
+  return raw.map(mapSummary);
+}
+
 // ---------------------------------------------------------------------------
 // Single transcription
 // ---------------------------------------------------------------------------