[python] Support data prefilters for full-text and hybrid search

[TheR1sing3un]

Purpose

Full-text search currently restricts pre_filter to partition columns, and hybrid queries reject data predicates when a full-text route is present. Support ordinary-column prefilters on data-evolution tables, applying the predicate before full-text Top-K selection and forwarding it to both hybrid routes.

Reuse the vector filter's snapshot-pinned data-read helper to collect exact matching row IDs from the filter columns, then pass that bitmap to native full-text search. This read uses full scalar-index coverage so partial scalar indexes cannot exclude rows covered by the full-text plan. Partition-only queries retain their pruning path, and vector candidate-refinement policy is unchanged. Raw fallback preserves the unfiltered BM25 corpus; full mode also covers selected partitions with no full-text index files. Document the additional filter-column read cost.

Tests

• Native full-text indexes with no scalar index, BTree and Bitmap; partial scalar coverage, mixed indexed/raw data and raw-only partitions.
• Non-partitioned tables, filtered Top-K, stable BM25 scores, AND/OR partition semantics, hybrid routing, empty results, historical snapshots/deletions and concurrent commits.
• Relevant multimodal, vector filtering, exact-filter resource cleanup, Ray filter exactness, primary-key golden data and global-index coverage regressions passed.
• Repository-configured Flake8, Apache license checks and Python 3.6 grammar checks passed.