Add Clock page with live DB time and TimeApiClient service

Introduced a new Clock page that displays and updates the current database server time every second by calling a backend API. Added the TimeApiClient service to handle API requests for the server time. Registered TimeApiClient in Program.cs and updated the navigation menu to include a link to the new Clock page. Includes error handling and custom UI styling for the clock display.

DbFirst.BlazorWebApp/Components/Layout/NavMenu.razor

@@ -31,6 +31,12 @@
                 <span class="bi bi-table-nav-menu" aria-hidden="true"></span> MassData
             </NavLink>
         </div>
+
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="clock">
+                <span class="bi bi-clock-nav-menu" aria-hidden="true"></span> Clock
+            </NavLink>
+        </div>
     </nav>
 </div>
 

DbFirst.BlazorWebApp/Components/Pages/Clock.razor

@@ -0,0 +1,100 @@
+@rendermode InteractiveServer
+@page "/clock"
+@inject TimeApiClient TimeApi
+@implements IAsyncDisposable
+
+<PageTitle>Clock</PageTitle>
+
+<h3>DB Server Clock</h3>
+
+<div class="clock-wrapper">
+    <div class="clock-display @(_error != null ? "clock-error" : "")">
+        @if (_dbTime.HasValue)
+        {
+            <span class="clock-time">@_dbTime.Value.ToString("HH:mm:ss")</span>
+            <span class="clock-date">@_dbTime.Value.ToString("dd.MM.yyyy")</span>
+        }
+        else if (_error != null)
+        {
+            <span class="clock-time">--:--:--</span>
+            <span class="clock-date text-danger">@_error</span>
+        }
+        else
+        {
+            <span class="clock-time">...</span>
+        }
+    </div>
+</div>
+
+<style>
+    .clock-wrapper {
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        height: 40vh;
+    }
+
+    .clock-display {
+        display: flex;
+        flex-direction: column;
+        align-items: center;
+        background: var(--bs-body-bg, #1e1e2e);
+        border: 2px solid var(--bs-border-color, #444);
+        border-radius: 1rem;
+        padding: 2rem 4rem;
+        box-shadow: 0 4px 24px rgba(0,0,0,0.3);
+    }
+
+    .clock-time {
+        font-size: 5rem;
+        font-weight: 700;
+        font-variant-numeric: tabular-nums;
+        letter-spacing: 0.1em;
+        color: var(--bs-primary, #0d6efd);
+    }
+
+    .clock-date {
+        font-size: 1.4rem;
+        margin-top: 0.5rem;
+        opacity: 0.75;
+    }
+
+    .clock-error .clock-time {
+        color: var(--bs-danger, #dc3545);
+    }
+</style>
+
+@code {
+    private DateTime? _dbTime;
+    private string? _error;
+    private Timer? _timer;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await TickAsync();
+        _timer = new Timer(async _ =>
+        {
+            await TickAsync();
+            await InvokeAsync(StateHasChanged);
+        }, null, TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(1));
+    }
+
+    private async Task TickAsync()
+    {
+        try
+        {
+            _dbTime = await TimeApi.InsertAndGetLastAsync();
+            _error = null;
+        }
+        catch (Exception ex)
+        {
+            _error = ex.Message;
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_timer != null)
+            await _timer.DisposeAsync();
+    }
+}