Adds account management and subscription features

Introduces new account pages for managing subscriptions, payment methods, and invoice history

Includes:
- Subscription plan selection view
- Payment method display component
- Invoice history table
- Account page layout and styling

Updates main layout to include new CSS files for account management

PlanTempus.Application/Features/Account/Pages/Index.cshtml

@@ -0,0 +1,45 @@
+@page "/konto"
+@using PlanTempus.Application.Features.Account.Pages
+@model PlanTempus.Application.Features.Account.Pages.IndexModel
+@{
+    ViewData["Title"] = "Abonnement & Konto";
+}
+
+<swp-page-container>
+
+    <!-- Page Header -->
+    <swp-page-header>
+        <swp-page-title>
+            <h1>Abonnement & Konto</h1>
+            <p>Administrer dit abonnement og betalingsinfo</p>
+        </swp-page-title>
+    </swp-page-header>
+
+    <!-- Subscription Section -->
+    <swp-account-section>
+        <swp-account-section-header>
+            <swp-account-section-title>
+                <i class="ph ph-crown"></i>
+                Dit abonnement
+            </swp-account-section-title>
+        </swp-account-section-header>
+
+        @await Component.InvokeAsync("SubscriptionPlans")
+    </swp-account-section>
+
+    <!-- Billing Section -->
+    <swp-account-section>
+        <swp-account-section-header>
+            <swp-account-section-title>
+                <i class="ph ph-credit-card"></i>
+                Betaling & Fakturaer
+            </swp-account-section-title>
+        </swp-account-section-header>
+
+        <swp-billing-grid>
+            @await Component.InvokeAsync("PaymentMethod")
+            @await Component.InvokeAsync("InvoiceHistory")
+        </swp-billing-grid>
+    </swp-account-section>
+
+</swp-page-container>