feat: Enhance user group management and transaction handling in stored procedures

- Improved user group deletion logic to accurately report success or failure.
- Updated user group renaming checks to prevent unintended inserts or updates.
- Added documentation on transaction blocking risks during full resets in stored procedures.
- Removed unnecessary login scripts from database project.

Fuchs_Database/dbo/Stored Procedures/fis_admin_setUserGroup.sql

@@ -17,9 +17,14 @@ BEGIN
 
 	DECLARE @createdID as TABLE ([id] varchar(5));
 
-	IF @auth > 1
+	-- Renaming an existing group (@usergroup_id supplied) requires that id to currently be an
+	-- active group; otherwise the MERGE below would silently INSERT it as a brand-new group
+	-- (rename-of-unknown-id becoming create) or resurrect/UPDATE a soft-deleted row without
+	-- clearing its DateDeleted (leaving it deleted yet renamed). @usergroup_id = NULL (create)
+	-- always passes this check.
+	IF @auth > 1 AND (@usergroup_id IS NULL OR EXISTS (SELECT * FROM [dbo].[fis_usergroups] WHERE [usergroup_id] = @usergroup_id AND [DateDeleted] IS NULL))
 	BEGIN
-		
+
 			MERGE [dbo].[fis_usergroups] as TARGET
 				USING (VALUES(	ISNULL(@usergroup_id, [dbo].[fis_fn_id] ('fis_usergroups'))
 								,ENCRYPTBYKEY(@enc_key, @name)