reading: split the book tracker into books, papers and articles (kind column + migration classifying 20 papers), segmented tabs with counts, article cards that open the link, owner + add link with server-side unfurl, kind switch on detail pages, /trackers/reading alias

src/lib/books/shared.ts

@@ -1,4 +1,18 @@
 // Shared (client + server) types and helpers for the book tracker.
+export const bookKinds = ['book', 'paper', 'article'] as const;
+export type BookKind = (typeof bookKinds)[number];
+export const isBookKind = (v: unknown): v is BookKind =>
+	typeof v === 'string' && (bookKinds as readonly string[]).includes(v);
+/** Tab labels and the `?kind=` value for each (plural, as in the URL). */
+export const kindTabs: Record<BookKind, { label: string; param: string }> = {
+	book: { label: 'books', param: 'books' },
+	paper: { label: 'papers', param: 'papers' },
+	article: { label: 'articles', param: 'articles' }
+};
+export function kindFromParam(param: string | null): BookKind {
+	const hit = bookKinds.find((k) => kindTabs[k].param === param || k === param);
+	return hit ?? 'book';
+}
 export const readingStatuses = ['want_to_read', 'reading', 'finished', 'abandoned'] as const;
 export type ReadingStatus = (typeof readingStatuses)[number];
 
@@ -24,6 +38,11 @@ export const formatPreference = ['epub', 'azw3', 'mobi', 'azw', 'fb2', 'pdf', 'c
 /** One card in the library. Public fields only, unless noted. */
 export type BookCard = {
 	id: number;
+	kind: BookKind;
+	url: string | null; // articles/papers on the web
+	site: string | null;
+	publishedAt: string | null;
+	excerpt: string | null; // articles only (short description)
 	title: string;
 	subtitle: string | null;
 	authors: string[];