fix(flows): create-flow dialog was still clamped to 384px — override sm: variant

PR #129 added `max-w-3xl` to the create-flow DialogContent thinking
it would widen the modal. It was a no-op. shadcn's DialogContent has
`sm:max-w-sm` baked into its default classes, and Tailwind-merge
treats `max-w-*` (base) and `sm:max-w-*` (sm-prefixed) as different
variants — both survive, and at every real desktop breakpoint the
sm-scoped 384px wins.

So the modal stayed at 384px regardless. Template cards continued to
look squished because the dialog never actually grew.

Override at the sm: variant directly. Use 4xl (896px) — gives each of
the three template cards roughly 270px of breathing room, enough for
the description to wrap to 4-5 lines instead of 10+.

Left a comment at the call site so the next person doesn't repeat
the same mistake.

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

src/app/(dashboard)/flows/page.tsx

@@ -245,7 +245,11 @@ export default function FlowsPage() {
       )}
 
       <Dialog open={createOpen} onOpenChange={setCreateOpen}>
-        <DialogContent className="max-w-3xl bg-slate-900 text-slate-100">
+        {/* `sm:max-w-4xl` not `max-w-4xl` — shadcn's DialogContent has
+            `sm:max-w-sm` baked into its default classes. Without the
+            sm: prefix our override applies at base only and the
+            sm-scoped 384px wins at every real desktop breakpoint. */}
+        <DialogContent className="sm:max-w-4xl bg-slate-900 text-slate-100">
           <DialogHeader>
             <DialogTitle>Create a new flow</DialogTitle>
             <DialogDescription className="text-slate-400">