[P2] record-change context does not hydrate multi-lookup (junction) fields #1872

Problem

Multi-value (multiple: true) lookup fields are stored in a junction table and are not hydrated onto the after-create record that a record-change flow sees — so conditions/interpolation referencing them are empty.

Repro

content cta_creation_default (record-after-create on content_piece): condition record.target_channels != null is false and node interpolation {piece.target_channels.0} doesn't resolve, even though target_channels persisted on the created piece. Flow never creates the default CTA. (Single-value lookups work fine.)

Expected

Record-change context should hydrate multi-lookup relationships (and support array-index interpolation), or offer relationship/junction-based triggering.

Affected

@objectstack/automation + objectql record hydration.

Found while runtime-testing objectstack-ai/templates (all 9 templates via objectstack dev all) on @objectstack 9.5.1. Build + typecheck pass; these only surface at runtime.