feat(stats): open calculated plan statistics (#65)

src/app/components/calendar-year/calendar-year.scss

@@ -221,6 +221,14 @@ summary:focus-visible {
 	}
 }
 
+.statistics-content {
+	display: grid;
+	gap: 1rem;
+}
+.statistics-summary {
+	grid-template-columns: minmax(0, 1fr);
+}
+
 .placement-explanation,
 .outcome-explanation,
 .trace-decisions {