Implement three divination modes, learn pages, and PM2 deploy on port 3130.

Add liuyao/bazi/combined flows with shared calc and AI infrastructure, 64-gua learn routes, and update Ubuntu PM2 deployment docs for port 3130.

Co-authored-by: Cursor <cursoragent@cursor.com>

components/learn/gua-footer.tsx

@@ -0,0 +1,16 @@
+import Link from "next/link";
+import { Button } from "@/components/ui/button";
+import { Sparkles } from "lucide-react";
+
+export default function GuaFooter({ guaMark }: { guaMark: string }) {
+  return (
+    <div className="mt-8 flex flex-wrap gap-3 border-t pt-6">
+      <Button asChild size="sm">
+        <Link href={`/liuyao?gua=${encodeURIComponent(guaMark)}`}>
+          <Sparkles size={16} className="mr-1" />
+          以此卦起卦
+        </Link>
+      </Button>
+    </div>
+  );
+}