Changes

Added

• Added QueryPlan.ParentLinks(childIndex) to return every incoming parent child link for a plan node, preserving stable plan traversal order and each parent's ChildLinks order.
• Added ResolvedParentLink, containing the parent PlanNode and the ChildLink that points to the child node.
• Added support for treating scalar Full Text Search Search Predicate child links as predicates in QueryPlan.IsPredicate, so downstream renderers can surface Full Text Search predicates without custom plan-shape logic.
• Added QueryPlan, plantree, and reference renderer tests for simple and compound Full Text Search predicate shapes.
• Added tests covering duplicate incoming links from the same parent, incoming links from multiple parents, empty and out-of-range ParentLinks lookups, returned-slice isolation, and compatibility with existing single-parent lookup behavior.

Changed

• Preserved existing GetParentNodeByChildIndex behavior while adding the all-parent-links API, keeping the existing single-parent map compatible for current callers.
• Clarified QueryPlan.IsVisible documentation: it controls operator-tree child-link visibility, hides scalar plan nodes unless the child link type is Scalar, and treats nil links as the root node.

Full Changelog

• v0.1.8...v0.1.9