feat(frontend): hide everything email related if it's disabled on the backend

Foxnouns.Backend/Controllers/Authentication/AuthController.cs

@@ -39,10 +39,10 @@ public class AuthController(
                 + $"&prompt=none&state={state}"
                 + $"&redirect_uri={HttpUtility.UrlEncode($"{config.BaseUrl}/auth/callback/discord")}";
 
-        return Ok(new UrlsResponse(discord, null, null));
+        return Ok(new UrlsResponse(config.EmailAuth.Enabled, discord, null, null));
     }
 
-    private record UrlsResponse(string? Discord, string? Google, string? Tumblr);
+    private record UrlsResponse(bool EmailEnabled, string? Discord, string? Google, string? Tumblr);
 
     public record AuthResponse(
         UserRendererService.UserResponse User,

Foxnouns.Backend/Controllers/Authentication/EmailAuthController.cs

@@ -100,6 +100,8 @@ public class EmailAuthController(
         [FromBody] CompleteRegistrationRequest req
     )
     {
+        CheckRequirements();
+
         var email = await keyCacheService.GetKeyAsync($"email:{req.Ticket}");
         if (email == null)
             throw new ApiError.BadRequest("Unknown ticket", "ticket", req.Ticket);
@@ -185,6 +187,8 @@ public class EmailAuthController(
     [Authorize("*")]
     public async Task<IActionResult> AddEmailAddressAsync([FromBody] AddEmailAddressRequest req)
     {
+        CheckRequirements();
+
         var emails = await db
             .AuthMethods.Where(m => m.UserId == CurrentUser!.Id && m.AuthType == AuthType.Email)
             .ToListAsync();