fix: implement Blazor-native login form to properly update authentication state

Problem: JavaScript login form saved tokens to localStorage but didn't notify
CustomAuthenticationStateProvider, causing [Authorize] pages to remain in
'loading' state indefinitely. The provider only reads tokens when:
1. GetAuthenticationStateAsync() is called (page load)
2. NotifyAuthenticationStateChanged() is triggered (UI updates)

But JavaScript login didn't trigger either, leaving the authentication state
stale.

Solution: Convert AdminLoginForm from HTML+JavaScript to pure Blazor component.
Now the login flow is:
1. User enters credentials in Blazor form
2. HttpClient POST to /api/auth/login
3. Save tokens to localStorage
4. Call CustomAuthenticationStateProvider.LoginAsync() directly
5. Blazor detects auth state change and re-evaluates [Authorize] pages
6. Dashboard [Authorize] page renders successfully

Result: Immediate authentication state update, no loading timeout on protected pages.

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

legacy/smartadmin/scripts/pages/checkboxandradio.js

@@ -0,0 +1,33 @@
+document.addEventListener("DOMContentLoaded", function () {
+    // Set the indeterminate state for the checkbox
+    document.getElementById("defaultIndeterminate").indeterminate = true;
+    // Get buttons
+    const checkboxToggleBtn = document.getElementById("js-checkbox-toggle");
+    const radioToggleBtn = document.getElementById("js-radio-toggle");
+    // Add click event listeners
+    if (checkboxToggleBtn) {
+        checkboxToggleBtn.addEventListener("click", toggleCheckbox);
+    }
+    if (radioToggleBtn) {
+        radioToggleBtn.addEventListener("click", toggleRadio);
+    }
+
+    // Function to toggle checkbox styles
+    function toggleCheckbox() {
+        let checkboxes = document.querySelectorAll(".demo-checkbox .form-check-input");
+        toggleText(this, "Change to CIRCLE", "Change back to default");
+        checkboxes.forEach(checkbox => checkbox.classList.toggle("rounded-circle"));
+    }
+
+    // Function to toggle radio button styles
+    function toggleRadio() {
+        let radios = document.querySelectorAll(".demo-radio .form-check-input");
+        toggleText(this, "Change to ROUNDED", "Change back to default");
+        radios.forEach(radio => radio.classList.toggle("rounded"));
+    }
+
+    // Function to toggle button text
+    function toggleText(element, text1, text2) {
+        element.textContent = element.textContent.trim() === text1 ? text2 : text1;
+    }
+});