feat(collections): add full CRUD with multi-collection assignment

packages/types/src/collection.ts

@@ -0,0 +1,15 @@
+export type Collection = {
+  id: number;
+  name: string;
+  description: string | null;
+  bookCount: number;
+  memberCount?: number;
+  createdAt: string;
+  updatedAt: string;
+};
+
+export type CollectionSummary = {
+  id: number;
+  name: string;
+  bookCount: number;
+};

packages/types/src/index.ts

@@ -1,5 +1,6 @@
 export * from "./auth";
 export * from "./book";
+export * from "./collection";
 export * from "./library";
 export * from "./query";
 export * from "./reader-settings";