wrap chain source, rescan and wallet-rename fields in real forms

three input sites lived in a div instead of a form, so pressing enter did
nothing and the button was the only way in. chain source url, rescan search
depth, and the inline wallet-rename field all get a <form onSubmit>, with
every non-submit button in each marked type="button" (the rescan card's
reset button was previously untyped, which would have submitted the form
once wrapped).

CoinsView.tsx has no text inputs (checkbox + buttons only) and
SeedPhraseInput.tsx deliberately hijacks enter to advance between word boxes
rather than submit, so both are left alone.

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

web/ChainSourceCard.tsx

@@ -80,7 +80,9 @@ export const ChainSourceCard = () => {
   const busy = save.isPending || forget.isPending;
   const meta = KINDS[kind];
 
-  const submit = async () => {
+  const submit = async (ev?: React.FormEvent) => {
+    ev?.preventDefault();
+    if (!trimmed || !dirty || busy) return;
     setError(null);
     setHeight(null);
     try {
@@ -111,7 +113,8 @@ export const ChainSourceCard = () => {
   };
 
   return (
-    <section className="max-w-2xl rounded-xl border border-border p-4">
+    // Typing a URL and pressing return is what anyone does; a div full of inputs swallows it silently.
+    <form onSubmit={submit} className="max-w-2xl rounded-xl border border-border p-4">
       <h3 className="mb-2 text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">Chain source</h3>
       <p className="mb-3 text-xs text-muted-foreground">
         Where on-chain wallets read balances and history. It sees every address this wallet asks about, so your own node
@@ -144,9 +147,6 @@ export const ChainSourceCard = () => {
         <Input
           value={url}
           onChange={(ev) => setUrl(ev.target.value)}
-          onKeyDown={(ev) => {
-            if (ev.key === 'Enter' && trimmed && dirty && !busy) void submit();
-          }}
           placeholder={meta.placeholder}
           disabled={isLoading || busy}
           className="h-8 font-mono text-xs"
@@ -155,12 +155,12 @@ export const ChainSourceCard = () => {
           spellCheck={false}
         />
         <div className="flex shrink-0 gap-2">
-          <Button size="sm" onClick={submit} disabled={!trimmed || !dirty || busy}>
+          <Button type="submit" size="sm" disabled={!trimmed || !dirty || busy}>
             {save.isPending ? <Loader2 className="mr-1.5 h-3.5 w-3.5 animate-spin" /> : null}
             {save.isPending ? 'Connecting…' : 'Save & connect'}
           </Button>
           {data?.custom && (
-            <Button size="sm" variant="outline" onClick={reset} disabled={busy} title="Back to the public default">
+            <Button type="button" size="sm" variant="outline" onClick={reset} disabled={busy} title="Back to the public default">
               <RotateCcw className="mr-1.5 h-3.5 w-3.5" />
               Reset
             </Button>
@@ -188,6 +188,6 @@ export const ChainSourceCard = () => {
           : `Using the built-in default (${data?.defaultUrl ?? '—'}), which rate-limits and can see every address you look up.`}{' '}
         {meta.hint}
       </p>
-    </section>
+    </form>
   );
 };