Add project files.

BudgetApp/Components/Pages/Login.razor

@@ -0,0 +1,70 @@
+@page "/login"
+@layout AuthLayout
+@using Microsoft.AspNetCore.Identity
+@inject SignInManager<ApplicationUser> SignInManager
+@inject NavigationManager Navigation
+
+<PageTitle>Budgeteer — Sign In</PageTitle>
+
+<h3 class="text-center mb-4">Sign In</h3>
+
+<EditForm Model="Model" OnValidSubmit="HandleLogin" FormName="login">
+    <DataAnnotationsValidator />
+
+    @if (!string.IsNullOrEmpty(errorMessage))
+    {
+        <div class="alert alert-danger">@errorMessage</div>
+    }
+
+    <div class="mb-3">
+        <label class="form-label">Email</label>
+        <InputText @bind-Value="Model.Email" class="form-control" placeholder="you@example.com" />
+        <ValidationMessage For="() => Model.Email" />
+    </div>
+
+    <div class="mb-3">
+        <label class="form-label">Password</label>
+        <InputText @bind-Value="Model.Password" type="password" class="form-control" />
+        <ValidationMessage For="() => Model.Password" />
+    </div>
+
+    <button type="submit" class="btn btn-primary w-100">Sign In</button>
+</EditForm>
+
+<p class="text-center mt-3">
+    Don't have an account? <a href="/register">Register</a>
+</p>
+
+@code {
+    [SupplyParameterFromForm]
+    private LoginModel Model { get; set; } = new();
+
+    private string? errorMessage;
+
+    private async Task HandleLogin()
+    {
+        errorMessage = null;
+
+        var result = await SignInManager.PasswordSignInAsync(
+            Model.Email, Model.Password, isPersistent: false, lockoutOnFailure: false);
+
+        if (result.Succeeded)
+        {
+            Navigation.NavigateTo("/", forceLoad: true);
+        }
+        else
+        {
+            errorMessage = "Invalid email or password.";
+        }
+    }
+
+    private sealed class LoginModel
+    {
+        [System.ComponentModel.DataAnnotations.Required(ErrorMessage = "Email is required")]
+        [System.ComponentModel.DataAnnotations.EmailAddress]
+        public string Email { get; set; } = string.Empty;
+
+        [System.ComponentModel.DataAnnotations.Required(ErrorMessage = "Password is required")]
+        public string Password { get; set; } = string.Empty;
+    }
+}