GoldenMatch

Changed

• BREAKING: result frames are now pyarrow.Table. DedupeResult.golden /
  .dupes / .unique and MatchResult.matched / .unmatched return
  pa.Table instead of pl.DataFrame (Polars-eviction W5, spec
  docs/superpowers/specs/2026-07-09-goldenmatch-polars-eviction-design.md).
  Migration is a one-liner: pl.from_arrow(result.golden). Inputs are
  unchanged (polars/pandas/arrow all accepted). to_csv and the notebook
  _repr_html_ render from Arrow natively.
• The arrow ingest lane runs the expression stages (row-ids, standardize,
  exact matchkeys) eagerly on the Frame seam; validation rules and auto-fix
  are seam-routed with probed arrow twins (RE2 regex owned contract).

Added

• Experimental GOLDENMATCH_FRAME=arrow lane: file ingest via pyarrow with a polars-parity reader corpus and a frame-backend differential harness (Polars-eviction W1).
• Fused auto-routing at the golden + match seams (controller-driven). The pipeline now auto-routes covered slow-path runs to the fused Arrow-native kernels, byte-identically, with no config change and per-surface kill-switches. Golden routing is the broad, LIVE win: at the golden seam the pipeline tries golden_fused.run_golden_fused_arrow by default on every covered slow-path config and reaches golden output at roughly 2x lower peak RSS; it declines to the classic builder (unchanged output) when the config is uncovered, the native kernel is absent, full ClusterProvenance lineage is requested, or the run is fast-path-eligible. Surfaced on DedupeResult.golden_fused_used; kill-switch GOLDENMATCH_GOLDEN_FUSED=0. Match routing is a documented DORMANT capacity-survival scaffold, not a live default. A controller post-step (maybe_route_fused_match) can short-circuit the match stage to the fused match kernel under an estimated-peak-RSS pressure gate, but the gate is deliberately narrow (auto_split=False, no identity/adaptive/memory/llm_boost/confidence_majority/full-provenance, not across-files-only, a covered weighted matchkey, and real memory pressure). Because zero-config auto-config commits auto_split=True and explicit configs bypass the controller, it effectively never fires by default. When it does fire it is a capacity mode that sheds scored_pairs, cluster-confidence, and lineage to survive; marked DedupeResult.match_fused_capacity_mode and controller-telemetry rule_name +fused_match_post_step. Kill-switch GOLDENMATCH_MATCH_FUSED=0; the wake-up path (a postflight-threshold fast-follow, or an explicit opt-in) is a follow-up. New env knobs (core/fused_routing.py, ExecutionPlan.use_fused_match): GOLDENMATCH_GOLDEN_FUSED, GOLDENMATCH_MATCH_FUSED, GOLDENMATCH_FUSED_PRESSURE_FRACTION (default 0.65), and the est-RSS calibration coefficients GOLDENMATCH_FUSED_RSS_SCALE / _BYTES_PER_PAIR / _BYTES_PER_CELL / _BLOCK_CONCURRENCY. No new native symbols (reuses the golden_fused / match_fused kernels), no new MCP tools / CLI commands / A2A skills.
• Fused golden-record kernel (golden_fused) - standalone, Arrow-native. A new one-FFI-call survivorship kernel (goldenmatch.core.golden_fused.run_golden_fused_arrow, gated by golden_fused_ready) builds golden records byte-identically to the classic build_golden_records_batch path at ~2x lower peak RSS (measured via scripts/bench_golden_fused_memcap.py + the bench-golden-fused-memcap workflow). It covers every Rust-portable survivorship rule in a single native call: scalar strategies (majority / unanimous / first_non_null / longest / source_priority / most_recent / most_complete), quality-weight tie-breaks, field_groups correlated survivorship, conditional field_rules (predicate AST lowered to a kernel RPN IR via golden_fused_predicate.lower_predicate / predicate_lowerable), cluster_overrides, and confidence_majority, plus per-field source_row_id provenance. Configs that need row-level validators, Python plugins, or LLM survivorship are declined (golden_fused_ready returns False) and fall through to the classic path unchanged. Not yet wired into the pipeline - this ships as a standalone, benched kernel (composability + peak-RSS win), so no existing user-facing behavior changes. Requires goldenmatch-native 0.1.13 (the depended-on golden_fused symbol ships in that wheel); without a republished wheel, pip install goldenmatch[native] users transparently degrade to the classic golden path (not a correctness bug - byte-identical output either way).
• MCP naming aliases for cross-language parity. The Python and TypeScript MCP servers previously exposed the same operations under different names (find_duplicates/dedupe, match_record/match, explain_match/explain_pair, profile_data/profile, plus TS's explain_cluster). Both servers now answer to both names via non-breaking aliases, so an agent trained against either server can call the other. The Python server gains dedupe/match/explain_pair/profile/explain_cluster; the TypeScript server gains find_duplicates/match_record/explain_match/profile_data. The API-parity gate enforces the nine names stay shared in parity/goldenmatch.yaml. Aliases are excluded from the goldensuite-mcp aggregated surface so the suite's profile still resolves to goldencheck's file-profiler.