b708a08fd0
Generalize the bottom-only handle machinery to all four sides. Top/Bottom keep their single-handle default; Left/Right are opt-in (default 0) so existing diagrams render unchanged. Handle IDs stay keyed off the bare side name at slot 0, keeping saved edges valid. - handleUtils: side-generic API (handleId, handlePositions, clampHandles, sideDefault, removedHandleIds, sideHandleCount); legacy bottom fns kept as delegating aliases - BaseNode + ProxmoxGroupNode render all sides via new shared SideHandles - updateNode remaps edges on any side's shrink (fallback to slot-0 / bottom) - serializer round-trips top/left/right_handles - NodeModal: spatial cross of -/N/+ steppers around a node preview, replacing the four stacked sliders; seeds per-type defaults - CustomStyleModal: per-type default connection points per side ha-relevant: yes