feat(web): render markdown tables as real HTML tables

Add remark-gfm plugin so react-markdown renders GFM table syntax as
proper <table> elements. Wrap tables in a scrollable container for
mobile-friendly horizontal scrolling on wide tables like ship stats
and weapon lists.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/index.css

@@ -562,11 +562,17 @@ details[open] > .rules-summary::before {
   margin-bottom: 2px;
 }
 
+.rules-content .table-wrap {
+  overflow-x: auto;
+  -webkit-overflow-scrolling: touch;
+  margin: var(--spacing-sm) 0;
+}
+
 .rules-content table {
   width: 100%;
   border-collapse: collapse;
-  margin: var(--spacing-sm) 0;
   font-size: 0.85rem;
+  white-space: nowrap;
 }
 
 .rules-content th,