feat(cypher): OPTIONAL MATCH + CASE execution for interactive-short-7 - #1061

Gap tests:
- safe_map_series: cudf + pd.Series mapping path (Engine.py:399-400)
- hop: missing_mask guard when edge_hop_col=None (hop.py:973)
- hop: empty edge_map_df else branch (hop.py:961-965)

DRY: extract _mk_abc_chain() helper in test_hop.py — 5 label tests refactored

CHANGELOG: fix call-site count (8, not 7); add #977 Tests entry (23 tests);
correct file list (no gfql_unified.py — that fix was in #1061)

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

…1066)

* chore: init branch for #977 cudf SIGSEGV fix

* fix(gfql): safe_map_series — replace cudf-incompatible Series.map(dict) with pandas bridge (#977)

cudf Series.map(dict/Series) triggers numba JIT which SIGSEGVs on RAPIDS 25.02.
Introduce safe_map_series() in Engine.py that bridges through pandas for cudf.
Apply at all 7 affected call sites: hop.py (4), chain.py (1), df_executor.py (2), pipeline.py (1).
Includes DGX smoke test + unit tests for safe_map_series + cudf guard regression tests.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* fix(gfql): guard hop.py edge_map usage against UnboundLocalError (#977)

edge_map is only assigned inside the edge_hop_col branch; line 974
used it unconditionally which raised UnboundLocalError when
edge_hop_col is None. Previously masked by SIGSEGV on 25.02.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* test(gfql): add cudf op bisect script for #977 25.02 SIGSEGV investigation

* test(gfql): bisect2 — minimal step-by-step crash location for #977 hop label_node_hops

* test(gfql): bisect3 — targeted hop label_node_hops cudf crash hunt

* fix(test): bisect3 typo fix

* fix(gfql): safe_map_series — use merge+to_arrow for cudf to avoid numba SIGSEGV on 25.02

* test(gfql): fix smoke test list-return query (unsupported), use simple ORDER BY

* fix(gfql): safe_map_series use to_arrow — CHANGELOG update, DGX-validated on 25.02+26.02 (#977)

* refactor(gfql): simplify safe_map_series — drop sort, drop_duplicates on lookup, cleaner cudf check

* test(gfql): amplify safe_map_series, hop labels, chain, ORDER BY — #977 coverage

* chore: remove temporary bisect scripts used to diagnose #977 SIGSEGV

* fix(types): safe_map_series — use DataframeLike/Union signature per Engine.py conventions

* fix(types): safe_map_series — use lazy_cudf_import + isinstance per Engine.py conventions

* fix(test): remove stray conflict marker from test_lowering.py

<<<<<<< HEAD line was left from incomplete conflict resolution
during rebase; caused SyntaxError in CI test collection.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* test(gfql): fourth amplification round + DRY — #977 coverage

Gap tests:
- safe_map_series: cudf + pd.Series mapping path (Engine.py:399-400)
- hop: missing_mask guard when edge_hop_col=None (hop.py:973)
- hop: empty edge_map_df else branch (hop.py:961-965)

DRY: extract _mk_abc_chain() helper in test_hop.py — 5 label tests refactored

CHANGELOG: fix call-site count (8, not 7); add #977 Tests entry (23 tests);
correct file list (no gfql_unified.py — that fix was in #1061)

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* test(gfql): fifth amplification round + DRY — #977 coverage

New tests:
- output_max_hops path (hop.py:834-891 fallback_map try/except + line-1011 post-filter)
- label_seeds=True with implicit starting_nodes (hop.py:843-859 both-branches path)
- numeric (int) node IDs through safe_map_series int→int hop labeling (hop.py:938)
- undirected label_seeds=False clears seed hop (hop.py:987-1000)

DRY: extract _mk_abcd_chain() helper — multi_hop_ordering + output_max_hops refactored

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* test(gfql): extend DGX smoke script with amplification-round cudf paths (#977)

New smoke tests cover:
- safe_map_series + pd.Series mapping (Engine.py:399-400)
- output_max_hops filtering (hop.py:834-891 fallback_map + line-1011 post-filter)
- label_seeds=True seed rows from node_hop_records (hop.py:843-859)
- label_seeds=False + undirected clears seed hop (hop.py:987-1000)

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* fix(test): smoke script — use to_arrow().to_pylist() for int cudf columns

to_pandas() on integer cudf Series SIGSEGVs on RAPIDS 25.02 (same numba
path as the original #977 bug). String columns are safe. Switch all numeric
hop value reads to to_arrow().to_pylist() to avoid the numba JIT trigger.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

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Co-authored-by: Claude Sonnet 4.6 <[email protected]>