[lmeyerov]

Summary

• Avoid duplicate cuDF columns when graph-return cuGraph algorithms temporarily use src/dst bindings.
• Keep the caller’s source/destination bindings by correcting returned-graph endpoint metadata before import.
• Preserve the original edge attributes on retained rows, including rows emitted by undirected cuGraph algorithms in reverse orientation.
• Preserve algorithm-filtered topology rather than restoring the full pre-algorithm edge frame.
• Reserve temporary row IDs across returned/original frames, including user-owned generated names.
• Reject one-sided undirected antiparallel attributes with conflicting values; retain identical attributes and exact orientations when both directions are returned.
• Remove redundant CI exclude overrides.

Fixes #2211

Evidence

• Base: origin/master@a3b3498ebe0d2b4f98d5f5d720a67e3d27fb58fe (fix(gexf): preserve endpoint attributes on import #2213 merge)

• Head: 05f841c9676a3b0ba8552dc63923ba14f1e20b74 / tree 0f74a5e8b263e94954f98c23b68d2641f364ad42

• DGX red baseline: src, dst, and both reproduce ValueError: Duplicate column names are not allowed; clean, source, target, and generated-name controls pass.

• F5 red: original user attr __cugraph_returned_edge_id__ reproduces KeyError at 30a493160c8d8c324627012740acddec7683ee49.

• Topology red: triangle plus tail, k_core(k=2) retained 4 edges and warned about mismatched edge-table lengths before this fix.

• Topology fix: out1 and out2 retain exactly the 3 triangle edges; retained labels survive, including reversed undirected orientations.

• Pandas matrix: 14 passed, 4 skipped, 23 deselected; Ruff clean.

• Directed scope: cuGraph 26.02 ego_graph(directed=True) retains both orientations with exact attrs; one-sided conflicting undirected output is rejected.

• DGX final matrix: RAPIDS graphistry/test-rapids-official:26.02-gfql, cuGraph 26.02.00, cuDF 26.02.01; focused tests 19 passed, 23 deselected, 3 subtests passed at the exact head. Receipts: plans/mcp-next-2211-2212-1955/worker/receipts/step11-p0035-dgx-05f841c9.txt and plans/mcp-next-2211-2212-1955/worker/receipts/final-2214-hosted-gates-05f841c9.txt.

• The full DGX class has three failures at unchanged 059e2ac53 and at this head: two 26.02 from_cugraph expectations and batched_ego_graphs availability. They are unchanged and outside the focused review scope.

• Changed-line coverage now includes graphistry/plugins/cugraph.py; focused cuGraph coverage remains DGX-native.

• Review response: duplicate (source, destination) pairs are explicitly rejected; retained output rows preserve one-to-one attribute identity; filtered topology is not restored.

• Final exact-head gates: CI run 39704024422 SUCCESS, CodeQL run 39704024437 SUCCESS, and RTD build 35313393 SUCCESS. Receipt: plans/mcp-next-2211-2212-1955/worker/receipts/final-2214-hosted-gates-05f841c9.txt.

P0035 directed graph-return durability

• Added TEST_CUGRAPH regression test_graph_return_directed_ego_preserves_antiparallel_attrs through public compute_cugraph("ego_graph", directed=True); expects both orientations with distinct attrs.
• Master red control on DGX (cuDF 26.02.01/cuGraph 26.02.00): returned 4 edges rather than the expected 2; amended focused suite: 19 passed, 23 deselected, 3 subtests passed.