refactor: relocate components to app directory structure

src/app/splash/components/splash-content.tsx

@@ -0,0 +1,18 @@
+"use client";
+/**
+ * Splash 内容文案
+ *
+ * 原始 Dart: lib/ui/splash/widgets/splash_content.dart
+ */
+import styles from "./splash-content.module.css";
+
+export function SplashContent() {
+  return (
+    <div className={styles.content}>
+      <h1 className={styles.title}>Chat with Elio, anytime, anywhere</h1>
+      <p className={styles.subtitle}>
+        A safe, private space to talk, share, and unwind — your AI companion who&apos;s always there.
+      </p>
+    </div>
+  );
+}