feat: implement osu! installation validation

src/pages/Login.svelte

@@ -0,0 +1,28 @@
+<script lang="ts">
+  import { ezppfarm } from '@/api/ezpp';
+
+  let username = $state('');
+  let password = $state('');
+
+  let errorMessage = $state('');
+  let isLoading = $state(false);
+
+  const performLogin = async () => {
+    isLoading = true;
+    errorMessage = '';
+
+    try {
+      const loginResult = await ezppfarm.login(username, password);
+        if (loginResult) {
+            // Handle successful login, e.g., redirect to the main app or store the token
+            console.log('Login successful:', loginResult);
+        } else {
+            errorMessage = 'Invalid username or password.';
+        }
+    } catch {
+      errorMessage = 'Login failed. Please check your credentials.';
+    } finally {
+      isLoading = false;
+    }
+  };
+</script>