Deck builder: sorting and a Price column

Adds the Library's Sort by control (plus a Quantity in deck option) to the
deck builder, applied within each section and group. The card table gets
an optional Price column showing the per-copy price, with the total for
the deck's copies in its tooltip. The toolbar now wraps on narrow screens.

Refs #6

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/styles.css

@@ -1704,6 +1704,10 @@ tbody tr:hover {
   }
 }
 
+.cell-price {
+  font-variant-numeric: tabular-nums;
+  white-space: nowrap;
+}
 .over-assigned {
   color: var(--warn);
   font-weight: 600;