fix: stabilize mini app login and safe area

src/GmRelay.Web/Program.cs

@@ -117,6 +117,25 @@ app.MapPost("/auth/telegram-webapp", async (
     return Results.Ok(new { redirectUrl = "/" });
 }).DisableAntiforgery();
 
+app.MapPost("/auth/telegram-login", async (
+    HttpContext context,
+    TelegramAuthService authService,
+    TelegramLoginPayload request) =>
+{
+    if (!authService.VerifyLoginPayload(request, out var telegramId, out var name))
+    {
+        return Results.Unauthorized();
+    }
+
+    var authProperties = new AuthenticationProperties { IsPersistent = true };
+    await context.SignInAsync(
+        CookieAuthenticationDefaults.AuthenticationScheme,
+        CreateTelegramPrincipal(telegramId, name),
+        authProperties);
+
+    return Results.Ok(new { redirectUrl = "/" });
+}).DisableAntiforgery();
+
 app.MapGet("/auth/status", (HttpContext context) =>
     Results.Ok(new { authenticated = context.User.Identity?.IsAuthenticated == true }));