gfql/cypher: bound-aliases NOT-pattern + IC10 unblock (#1031 slice 2 phase 2c)

[lmeyerov]

Parent: #1031
Depends on: #1235

This issue tracks #1031 slice 2 phase 2c work after anti-semi runtime lands.

Scope

• Support bound-aliases NOT-pattern shapes, for example MATCH (a)-[:R]->(b) WHERE NOT (b)-[:R]-(a)
• Validate composition with existing row-NOT logic
• Unblock IC10 shape under direct Cypher path
• Add or adjust TCK xfail contract entries as needed

Reference docs

• plans/1031-slices-2-3-4/HANDOFF.md
• plans/1031-slices-2-3-4/findings/slice-2-phase-2b-engine.md