Enchance conditional node saving

[matKlju]

@1AhmedYasser

[1AhmedYasser]

@matKlju

AS A Service Creator
I WANT to control AND / OR / NOT between individual conditions inside a condition group, and have those settings (including NOT) actually persist when I save
SO THAT I can build mixed AND/OR logic without wrapping every pair of conditions in an artificial subgroup, and trust that the saved YAML matches what I configured in the UI

Acceptance Criteria

• Each condition row in a group has its own AND/OR/NOT connector to the row before it (the first row in a group has no connector, since there's nothing to combine it with)
• Mixing AND and OR within the same group no longer requires nesting a nested subgroup for every pair of conditions
• Nested subgroups can be connected to their sibling rows via the same per-row AND/OR/NOT connector
• The group-level NOT toggle still negates the group's entire combined expression as one unit (!(...))
• Toggling the group-level NOT and saving now correctly persists into the generated condition string / YAML (previously it was silently dropped on save)
• Previously saved conditions (single AND/OR per group) continue to produce the exact same compiled condition string after this change