feat(authors): collapse series on author pages (#1271)

Reduce large author listings to one card per series while preserving book counts, scoped visibility, and row-based pagination. Compute both totals in the collapsed query so deep pages remain consistent without a second author-wide scan.

Closes #301

Co-authored-by: neon <18559658+neonsolstice@users.noreply.github.com>

packages/types/src/author.ts

@@ -43,7 +43,15 @@ export type AuthorsPage = {
   size: number;
 };
 
-export type AuthorBooksPage = BooksPage;
+/**
+ * `total` counts rows in the page's own unit, so it is the number of cards once
+ * `collapseSeries` folds a series into one card - that is what paginating and "is there more"
+ * have to be driven by. `bookTotal` stays the number of books behind those rows, for the
+ * places that count books rather than cards. The two are equal while the list is flat.
+ */
+export type AuthorBooksPage = BooksPage & {
+  bookTotal: number;
+};
 
 export type MergeAuthorsResult = {
   target: AuthorDetail;

packages/types/src/series-collapse.ts

@@ -3,6 +3,13 @@ export type SeriesCollapsePreferences = {
   libraries: Record<string, boolean>;
   collections: Record<string, boolean>;
   smartScopes?: Record<string, boolean>;
+  /**
+   * Author pages share one flag instead of a per-author bucket: the bucket would grow with every
+   * author browsed, and "collapsed for King but not for Pratchett" is not a distinction anyone
+   * asks for. Absent means off, so an upgrade leaves author pages flat even for a user whose
+   * {@link SeriesCollapsePreferences.global} is on.
+   */
+  authorPages?: boolean;
 };
 
 export type CollapsedSeriesInfo = {
@@ -18,9 +25,12 @@ export type CollapsedSeriesInfo = {
 
 export function resolveCollapsePreference(
   prefs: SeriesCollapsePreferences | undefined,
-  ctx: { libraryId?: number; collectionId?: number; smartScopeId?: number },
+  ctx: { libraryId?: number; collectionId?: number; smartScopeId?: number; authorPages?: boolean },
 ): boolean {
   if (!prefs) return false;
+  // Author pages resolve to their own flag and stop there - they deliberately do not inherit the
+  // global default, and the library filter on an author page is a filter, not a scope to override.
+  if (ctx.authorPages) return prefs.authorPages ?? false;
   if (ctx.smartScopeId !== undefined) {
     const override = prefs.smartScopes?.[String(ctx.smartScopeId)];
     if (override !== undefined) return override;