style(backend): apply dotnet format whitespace normalization

- Applied dotnet format to 24 files in backend/
- Corrects spacing, indentation, and formatting consistency
- No functional changes to code logic

Ultraworked with Sisyphus <https://github.com/code-yeongyu/oh-my-opencode>
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/WorkClub.Api/Services/MemberSyncService.cs

@@ -42,7 +42,7 @@ public class MemberSyncService
 
         var email = httpContext.User.FindFirst("email")?.Value ?? httpContext.User.FindFirst("preferred_username")?.Value ?? "unknown@example.com";
         var name = httpContext.User.FindFirst("name")?.Value ?? email.Split('@')[0];
-        
+
         var roleClaim = httpContext.User.FindFirst(System.Security.Claims.ClaimTypes.Role)?.Value ?? "Member";
         var clubRole = roleClaim.ToLowerInvariant() switch
         {