feat(frontend): Improve System page and TransactionsTable UX.

System page improvements:
- Add View Logs button to each sync operation with modal dialog
- Implement responsive design for mobile devices
- Remove redundant error count indicators
- Show full transaction text on mobile ("X new transactions")

TransactionsTable improvements:
- Use display_name instead of name • institution_id format
- Show only clean account display names in transaction rows

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/src/components/TransactionsTable.tsx

@@ -190,8 +190,7 @@ export default function TransactionsTable() {
               <div className="text-xs text-muted-foreground space-y-1">
                 {account && (
                   <p className="truncate">
-                    {account.name || "Unnamed Account"} •{" "}
-                    {account.institution_id}
+                    {account.display_name || "Unnamed Account"}
                   </p>
                 )}
                 {(transaction.creditor_name || transaction.debtor_name) && (
@@ -486,8 +485,7 @@ export default function TransactionsTable() {
                             <div className="text-xs text-muted-foreground space-y-1 mt-1">
                               {account && (
                                 <p className="break-words">
-                                  {account.name || "Unnamed Account"} •{" "}
-                                  {account.institution_id}
+                                  {account.display_name || "Unnamed Account"}
                                 </p>
                               )}
                               {(transaction.creditor_name ||