fix(gfql/row): resolve bare relationship alias in row expressions (#1072)

[lmeyerov]

Summary

Fixes #1072. Bare edge aliases in row expressions (e.g. select([("rel", "workAt")]), where_rows("workAt IS NOT NULL")) raised unsupported token in row expression: 'workAt' because _gfql_resolve_token's bare-alias fallback only knew about node aliases ({alias}.{node_id} lookup).

Before / after

Before — direct GFQL chain over a bindings row table:

ops = [
    n({"label__Person": True}, name="friend"),
    e_forward(edge_match={"type": "WORKS_AT"}, name="workAt"),
    n({"label__Company": True}, name="company"),
    rows(table="nodes", binding_ops=[...]),
    select(items=[("rel", "workAt")]),
]
g.gfql(ops)
# GFQLTypeError: Error executing 'select': unsupported token in row expression: 'workAt'

After: returns a Cypher-style rendering, matching what RETURN <relAlias> already produces via result_postprocess:

                            rel
0  [:WORKS_AT {workFrom: 2010}]

Change

graphistry/compute/gfql/row/pipeline.py:

• Extend the bare-alias fallback in _gfql_resolve_token so an edge alias resolves to either the edge-id column ({alias}.{_edge}) when present, or to a rendered [:TYPE {props}] string via the new _gfql_render_relationship_alias helper.
• The renderer skips _source / _destination / _edge / __* columns and the alias-indicator column ({alias}.{alias}); rows whose alias columns are all null become pd.NA.

Tests

graphistry/tests/compute/gfql/test_row_pipeline_ops.py::TestRelationshipAliasInRowExpression (3 new tests):

• bare select(items=[("rel", "workAt")]) renders the Cypher string,
• select(items=[("yr", "workAt.workFrom")]) keeps working (regression guard),
• where_rows("workAt IS NOT NULL") keeps the row.

Full graphistry/tests/compute/gfql/ suite: 1576 passed, 87 skipped, 15 xfailed.

Test plan

• Run python -m pytest graphistry/tests/compute/gfql/
• ./bin/lint.sh and ./bin/mypy.sh on touched files