Fix transparent sticky name column on horizontal scroll

td.col-name had background:inherit, which resolved to the parent
<tr>'s (unset, transparent) background instead of the opaque white/
gray already applied to sibling cells. That let scrolled-under
columns show through the sticky first column. The generic tr.r-item
td rules already give col-name an opaque background, so the
override was both redundant and the bug.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

index.php

@@ -126,7 +126,6 @@ tr.r-header.L1 td{background:#1e293b!important;color:#94a3b8}
 /* ── item rows ── */
 tr.r-item td{background:#fff;border-bottom:1px solid #f1f5f9}
 tr.r-item:nth-child(even) td{background:#f8fafc}
-tr.r-item td.col-name{background:inherit}
 
 /* ── subtotal rows ── */
 tr.r-subtotal td{