fix(layout): restore Zibll float dual-column so content no longer overlaps sidebar

Align main shells to main.container > .content-wrap + .sidebar siblings, drop
content-shell padding on dual-column hosts, and remove route flex overrides that
disabled the negative-margin sidebar math.

assets/css/routes/archives.css

@@ -4,21 +4,7 @@
  * @package AKSRT
  */
 
-.page-template-archives .content-wrap {
-	display: flex;
-	flex-wrap: wrap;
-	gap: 20px;
-}
-
-.page-template-archives .content-layout {
-	flex: 1 1 0;
-	min-width: 0;
-}
-
-.page-template-archives .sidebar {
-	flex: 0 0 300px;
-	max-width: 100%;
-}
+/* Dual-column geometry owned by layout.css site-layout float rules (Zibll). */
 
 .archives-month-list {
 	list-style: none;
@@ -76,8 +62,3 @@
 	margin-left: 6px;
 }
 
-@media (max-width: 991px) {
-	.page-template-archives .sidebar {
-		flex: 1 1 100%;
-	}
-}