feat(api): add GET /api/library/albums handler

Implements the paged alpha-sorted album list endpoint used by the M6a
wrapping-grid SPA page. Mirrors handleListArtists alpha branch using
ListAlbumsAlphaWithArtist + CountAlbums; 2/2 integration tests pass.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/api/library_albums.go

@@ -0,0 +1,41 @@
+package api
+
+import (
+	"net/http"
+
+	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
+)
+
+// handleListLibraryAlbums implements GET /api/library/albums. Mirrors
+// /api/artists?sort=alpha but for albums. The new wrapping-grid page on
+// the SPA infinite-scrolls against this endpoint via TanStack
+// createInfiniteQuery.
+func (h *handlers) handleListLibraryAlbums(w http.ResponseWriter, r *http.Request) {
+	limit, offset, err := parsePaging(r.URL.Query())
+	if err != nil {
+		writeErr(w, http.StatusBadRequest, "bad_request", err.Error())
+		return
+	}
+	q := dbq.New(h.pool)
+	rows, err := q.ListAlbumsAlphaWithArtist(r.Context(), dbq.ListAlbumsAlphaWithArtistParams{
+		Limit: int32(limit), Offset: int32(offset),
+	})
+	if err != nil {
+		h.logger.Error("api: list library albums", "err", err)
+		writeErr(w, http.StatusInternalServerError, "server_error", "lookup failed")
+		return
+	}
+	total, err := q.CountAlbums(r.Context())
+	if err != nil {
+		h.logger.Error("api: count albums", "err", err)
+		writeErr(w, http.StatusInternalServerError, "server_error", "count failed")
+		return
+	}
+	items := make([]AlbumRef, 0, len(rows))
+	for _, row := range rows {
+		items = append(items, albumRefFrom(row.Album, row.ArtistName, 0, 0))
+	}
+	writeJSON(w, http.StatusOK, Page[AlbumRef]{
+		Items: items, Total: int(total), Limit: limit, Offset: offset,
+	})
+}