Fix tx list overflow: use truncate on left spans, shrink-0+pl-2 on right

Left-side spans (age, address) get tailwind truncate class so they
can't push the row wider than its container. Right-side spans (direction,
amount) get shrink-0 so they keep their full text. Also added
overflow-hidden on #tx-list container.

src/popup/index.html

@@ -239,7 +239,7 @@
                     <div class="border-b border-border pb-1 mb-1">
                         <h2 class="font-bold">Transactions</h2>
                     </div>
-                    <div id="tx-list">
+                    <div id="tx-list" class="overflow-hidden">
                         <div class="text-muted text-xs py-1">Loading...</div>
                     </div>
                 </div>