Module fusion 

Score fusion algorithms for combining results from multiple search sources.

Extracted from procedure_call.rs for reuse by similar_to and hybrid search procedures.

Functions

fuse_rrf

Reciprocal Rank Fusion (RRF) for combining ranked result lists.

fuse_rrf_point

Multi-source RRF fusion for point computation context.

fuse_weighted

Weighted fusion: alpha * vec_score + (1 - alpha) * fts_score.

fuse_weighted_multi

Multi-source weighted fusion for similar_to.