case 4713 - customer contacts hold and act with customer roles only

Users who may edit contacts but not users (Service, Sales, Accounting) could
give a contact login any role, BizAdmin and OpsAdmin included, and roles are
what every check uses (security review F28). Now:
- saving a Customer or HeadOffice user with any role other than Customer or
  CustomerRestricted is refused (error on Roles);
- UserBiz.EffectiveRoles masks a contact's roles to the customer roles wherever
  they are applied: the token middleware, download-key routes, and the
  notification subscriber check, so contacts that already have staff roles
  stored act without them.

Checked: Service creating a contact with BizAdmin refused, with Customer works;
a contact with OpsAdmin stored in the database gets 403 downloading a log file.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/AyaNova/Startup.cs

@@ -406,7 +406,8 @@ namespace AyaNova
 
                     //get the user record
                     var u = await ct.User.AsNoTracking().Where(a => a.Id == userId).Select(m => new { roles = m.Roles, name = m.Name, m.UserType, id = m.Id, translationId = m.UserOptions.TranslationId, currentAuthToken = m.CurrentAuthToken }).FirstAsync();
-                    context.Request.HttpContext.Items["AY_ROLES"] = u.roles;
+                    //case 4713: a customer contact acts only with the customer roles, whatever roles are stored
+                    context.Request.HttpContext.Items["AY_ROLES"] = UserBiz.EffectiveRoles(u.UserType, u.roles);
                     context.Request.HttpContext.Items["AY_USERNAME"] = u.name;
                     context.Request.HttpContext.Items["AY_USER_ID"] = u.id;
                     context.Request.HttpContext.Items["AY_TRANSLATION_ID"] = u.translationId;