refactor(cards): BuildSections through the builder

The dashboard section builder — feeding both the dashboard JSON pin
surface and the SSR dashboard — now calls BookCardsFromMediaItems on
ds.Items. libTypes already arrives as a BuildSections parameter
(once per request); the literal only duplicated the badge lookup.

internal/handlers/dashboard.go

@@ -3,7 +3,6 @@ package handlers
 import (
 	"bookhoard/internal/database"
 	"bookhoard/internal/services"
-	"bookhoard/internal/utils"
 	"context"
 	"log"
 	"net/http"
@@ -200,18 +199,7 @@ func BuildSections(sections []services.DashboardSection, currentLibraryID, libra
 			}
 		}
 
-		bookCards := make([]BookInfo, len(ds.Items))
+		bookCards := BookCardsFromMediaItems(ds.Items, libTypes)
-		for i, item := range ds.Items {
-			itemUUID, _ := uuid.FromBytes(item.ID.Bytes[0:16])
-			bookCards[i] = BookInfo{
-				MediaItemID:    itemUUID.String(),
-				Title:          item.Title,
-				Author:         textToString(item.Author),
-				CoverImagePath: utils.ResolveMediaURL(item.LibraryID, item.CoverImagePath),
-				FormatGroup:    item.FormatGroup,
-				Badge:          MediaBadgeKind(item.FormatGroup, libTypes[uuid.UUID(item.LibraryID.Bytes).String()]),
-			}
-		}
 
 		result = append(result, SectionData{
 			ID:           ds.CollectionName,