Build the effective roles in a single pass

The list restarts whenever a higher priority is found, rather than collecting
every role and filtering afterwards.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

exp_roles/module/control.lua

@@ -168,23 +168,20 @@ local function get_effective_roles(player_name)
         role_ids[#role_ids + 1] = script_data.default_role_id
     end
 
-    local roles, highest_priority = {}, nil
+    -- Only the roles with the highest priority apply, so the list restarts
+    -- whenever a higher priority is found
+    local rtn, highest_priority = {}, nil
     for _, role_id in pairs(role_ids) do
         local role = script_data.roles[role_id]
         if role then
-            roles[#roles + 1] = role
             if highest_priority == nil or role.priority > highest_priority then
                 highest_priority = role.priority
-            end
-        end
-    end
-
-    local rtn = {}
-    for _, role in pairs(roles) do
-        if role.priority == highest_priority then
+                rtn = { role }
+            elseif role.priority == highest_priority then
                 rtn[#rtn + 1] = role
             end
         end
+    end
     return rtn
 end