* fix: resolve chunks for observation results via source_memory_ids
Observations have no direct chunk_id (they are synthesized from source
memories). When include_chunks=True and fact_type includes 'observation',
chunks were silently returned as None.
Fix collects source chunk_ids via a single JOIN on source_memory_ids,
using array_position to preserve observation rank order so observation
source chunks are interleaved at the correct position rather than
appended after all direct-fact chunks.
* fix: use correct run_consolidation method name in test
cb6d1c469c