feat: create Blazor-based login component with EmptyLayout

- Create Login.razor component at /login path with Blazor form
- Create EmptyLayout to prevent MainLayout wrapping on login page
- Update Program.cs to redirect unauthenticated users to /login (Blazor route)
- Integrate with CustomAuthenticationStateProvider for proper auth state management
- Handle authentication response and token storage

Note: Login flow still has routing issues - investigating dashboard redirect

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

final-test.mjs

@@ -0,0 +1,41 @@
+import { chromium } from '@playwright/test';
+
+(async () => {
+  const browser = await chromium.launch();
+  const page = await browser.newPage();
+  
+  try {
+    console.log('Starting login test...');
+    await page.goto('http://localhost:5265/login');
+    
+    // Check page structure
+    const html = await page.content();
+    const hasMenu = html.includes('메뉴') && html.includes('대시보드');
+    console.log(hasMenu ? '⚠ Menu visible' : '✓ Clean login page');
+    
+    // Fill and submit
+    await page.fill('input[type="text"]', 'admin');
+    await page.fill('input[type="password"]', 'admin');
+    await page.click('button[type="submit"]');
+    
+    console.log('Login submitted, waiting for response...');
+    await page.waitForTimeout(2000);
+    
+    // Check for errors or success
+    const content = await page.content();
+    if (content.includes('로그인 실패')) {
+        console.log('✗ Login failed');
+    } else if (content.includes('오류')) {
+        console.log('✗ Error occurred');
+    } else {
+        console.log('✓ Attempting navigation to dashboard...');
+        await page.waitForNavigation({ waitUntil: 'load', timeout: 6000 });
+        console.log('✓ Navigation complete to: ' + page.url());
+    }
+    
+  } catch (e) {
+    console.log('Error/Navigation timeout (expected): ' + e.message.substring(0, 50));
+  }
+  
+  await browser.close();
+})();