refactor(frontend): address review feedback on wallet on-chain mode

- OnchainTransactionsTable: don't flash the empty state while SWR is
  still loading; only render it once transactions is defined AND empty.
- OnchainTransactionsTable: add DialogDescription to the details dialog
  so DialogContent has an accessible description (fixes Radix's dev
  warning and improves screen-reader flow).
- OnchainTransactionsTable: swap the copy-tx-id native button for the
  shadcn Button in ghost/icon-xs — kept the row-level button native
  because the shadcn variants (justify-center, h-9, bg) fight the
  custom-shaped row surface.
- Wallet: dynamic aria-label on the balance-mode toggle so the current
  state is announced (previously "Switch balance mode" hid the visible
  label).
- Wallet: align on "On-chain Balance" (repo convention — ~18 other uses)
  instead of "On-Chain Balance".
- Wallet: gate the "Open Your First Channel" alert on channels being
  loaded so it doesn't flash while useChannels() is resolving.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/components/wallet/OnchainTransactionsTable.tsx

@@ -14,6 +14,7 @@ import { Button } from "src/components/ui/button";
 import {
   Dialog,
   DialogContent,
+  DialogDescription,
   DialogFooter,
   DialogHeader,
   DialogTitle,
@@ -136,6 +137,11 @@ function OnchainTransactionRow({
           <DialogTitle className={cn(isPending && "animate-pulse")}>
             {`${typeStateText} On-chain Transaction`}
           </DialogTitle>
+          <DialogDescription>
+            {isPending
+              ? "This transaction is pending confirmation."
+              : "This transaction has been confirmed on the blockchain."}
+          </DialogDescription>
         </DialogHeader>
         <div className="space-y-6 text-sm">
           <div
@@ -174,14 +180,15 @@ function OnchainTransactionRow({
               <p className="break-all font-mono text-muted-foreground">
                 {tx.txId}
               </p>
-              <button
+              <Button
                 type="button"
-                className="shrink-0 cursor-pointer text-muted-foreground"
+                variant="ghost"
+                size="icon-xs"
                 onClick={() => copyToClipboard(tx.txId)}
                 aria-label="Copy transaction ID"
               >
-                <CopyIcon className="size-4" />
-              </button>
+                <CopyIcon />
+              </Button>
             </div>
           </div>
         </div>
@@ -213,7 +220,11 @@ export function OnchainTransactionsTable() {
   const { data: info } = useInfo();
   const { data: transactions } = useOnchainTransactions();
 
-  if (!transactions?.length) {
+  if (!transactions) {
+    return null;
+  }
+
+  if (transactions.length === 0) {
     return (
       <div className="flex w-full flex-1 flex-col">
         <EmptyState

frontend/src/screens/wallet/index.tsx

@@ -118,29 +118,34 @@ function Wallet() {
           balances.lightning.totalSpendable * 0.1 && (
           <LowReceivingCapacityAlert />
         )}
-      {!isOnchainMode && hasChannelManagement && !hasChannelsOpen && (
-        <Alert>
-          <AlertTriangleIcon className="h-4 w-4" />
-          <AlertTitle>Open Your First Channel</AlertTitle>
-          <AlertDescription className="inline">
-            You won't be able to receive or send payments until you{" "}
-            <Link className="underline" to="/channels/first">
-              open your first channel
-            </Link>
-            .
-          </AlertDescription>
-        </Alert>
-      )}
+      {!isOnchainMode &&
+        hasChannelManagement &&
+        channels &&
+        !hasChannelsOpen && (
+          <Alert>
+            <AlertTriangleIcon className="h-4 w-4" />
+            <AlertTitle>Open Your First Channel</AlertTitle>
+            <AlertDescription className="inline">
+              You won't be able to receive or send payments until you{" "}
+              <Link className="underline" to="/channels/first">
+                open your first channel
+              </Link>
+              .
+            </AlertDescription>
+          </Alert>
+        )}
       <div className="flex w-full flex-col items-center gap-8 pt-12 pb-16 text-center">
         <div className="flex flex-col items-center gap-4">
           {hasChannelManagement ? (
             <button
               type="button"
               onClick={toggleBalanceMode}
-              aria-label="Switch balance mode"
+              aria-label={`Toggle balance mode, currently ${
+                isOnchainMode ? "On-chain Balance" : "Spending Balance"
+              }`}
               className="inline-flex items-center justify-center gap-1 text-xs font-medium leading-none uppercase text-muted-foreground transition-colors hover:text-foreground"
             >
-              {isOnchainMode ? "On-Chain Balance" : "Spending Balance"}
+              {isOnchainMode ? "On-chain Balance" : "Spending Balance"}
               <ArrowDownUpIcon aria-hidden className="size-3 shrink-0" />
             </button>
           ) : (