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.

category.php

@@ -193,7 +193,7 @@ foreach ($custom_dimensions as $dim) {
 
 if (function_exists('aksrt_archive_open_shell')) {
 	aksrt_archive_open_shell([
-		'main_class'  => 'site-main container content-shell content-shell--stream',
+		'main_class'  => 'site-main container',
 		'has_sidebar' => $has_sidebar,
 		'top_fluid'   => ['cat_top_fluid'],
 		'page_kind'   => 'category',