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/RescanCard.tsx

@@ -37,8 +37,14 @@ export const RescanCard = ({ walletId }: RescanCardProps) => {
   const parsed = Number(gapLimit);
   const depth = gapLimit.trim() && Number.isInteger(parsed) && parsed > 0 ? parsed : null;
 
+  const submit = (ev?: React.FormEvent) => {
+    ev?.preventDefault();
+    if (running || rescan.isPending) return;
+    rescan.mutate(depth ? { gapLimit: depth } : {});
+  };
+
   return (
-    <section className="max-w-2xl rounded-xl border border-border p-4">
+    <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">
         Find missing coins
       </h3>
@@ -50,9 +56,9 @@ export const RescanCard = ({ walletId }: RescanCardProps) => {
 
       <div className="flex flex-wrap items-center gap-2">
         <Button
+          type="submit"
           size="sm"
           variant="outline"
-          onClick={() => rescan.mutate(depth ? { gapLimit: depth } : {})}
           disabled={running || rescan.isPending}
         >
           {running || rescan.isPending ? (
@@ -82,7 +88,7 @@ export const RescanCard = ({ walletId }: RescanCardProps) => {
       </div>
 
       {state && <Status state={state} />}
-    </section>
+    </form>
   );
 };