Delete owned campaigns on user delete and preserve campaign characters

RpgRoller/Services/GameService.cs

@@ -321,10 +321,19 @@ public sealed class GameService : IGameService
                 return ServiceResult<bool>.Failure("user_not_found", "User was not found.");
 
             var gmCampaignIds = m_CampaignsById.Values.Where(campaign => campaign.GmUserId == targetUser.Id).Select(campaign => campaign.Id).ToArray();
+            var gmCampaignIdSet = gmCampaignIds.ToHashSet();
+            var preservedCharacterIds = m_CharactersById.Values
+                .Where(character => character.CampaignId.HasValue && gmCampaignIdSet.Contains(character.CampaignId.Value))
+                .Select(character => character.Id)
+                .ToHashSet();
+
             foreach (var campaignId in gmCampaignIds)
                 DeleteCampaignLocked(campaignId);
 
-            var ownedCharacterIds = m_CharactersById.Values.Where(character => character.OwnerUserId == targetUser.Id).Select(character => character.Id).ToArray();
+            var ownedCharacterIds = m_CharactersById.Values
+                .Where(character => character.OwnerUserId == targetUser.Id && !preservedCharacterIds.Contains(character.Id))
+                .Select(character => character.Id)
+                .ToArray();
             foreach (var characterId in ownedCharacterIds)
                 DeleteCharacterLocked(characterId);