added Success page for submissions

app/api/submit/settings/success/page.tsx

@@ -0,0 +1,72 @@
+// app/submit/settings/success/page.tsx
+"use client";
+
+import Link from "next/link";
+import { useSearchParams } from "next/navigation";
+import { useMemo } from "react";
+
+type Target =
+  | "settings_fiber"
+  | "settings_co2gan"
+  | "settings_co2gal"
+  | "settings_uv";
+
+const TARGET_TO_LIST: Record<Target, string> = {
+  settings_fiber: "/fiber-settings",
+  settings_co2gan: "/co2-gantry-settings",
+  settings_co2gal: "/co2-galvo-settings",
+  settings_uv: "/uv-settings",
+};
+
+const TARGET_LABEL: Record<Target, string> = {
+  settings_fiber: "Fiber",
+  settings_co2gan: "CO₂ Gantry",
+  settings_co2gal: "CO₂ Galvo",
+  settings_uv: "UV",
+};
+
+export default function SuccessPage() {
+  const sp = useSearchParams();
+  const id = (sp.get("id") || "").trim();
+  const target = (sp.get("target") || "settings_fiber") as Target;
+
+  const listHref = TARGET_TO_LIST[target] || "/projects";
+  const targetLabel = TARGET_LABEL[target] || "Settings";
+
+  const title = useMemo(
+    () => `Settings Submitted${id ? ` (#${id})` : ""}`,
+    [id]
+  );
+
+  return (
+    <main className="max-w-2xl mx-auto py-10 px-4 space-y-6">
+      <div className="space-y-2">
+        <h1 className="text-2xl font-semibold">{title}</h1>
+        <p className="text-sm text-muted-foreground">
+          Your submission was received successfully.
+        </p>
+      </div>
+
+      <div className="grid gap-3 sm:grid-cols-2">
+        <Link
+          className="inline-flex items-center justify-center rounded border px-3 py-2 hover:bg-muted"
+          href={`/submit/settings?target=${encodeURIComponent(target)}`}
+        >
+          Submit Another ({targetLabel})
+        </Link>
+        <Link
+          className="inline-flex items-center justify-center rounded border px-3 py-2 hover:bg-muted"
+          href={listHref}
+        >
+          Go to {targetLabel} Database
+        </Link>
+      </div>
+
+      {id ? (
+        <p className="text-xs text-muted-foreground">
+          Reference ID: <span className="font-mono">{id}</span>
+        </p>
+      ) : null}
+    </main>
+  );
+}