test(bench): add a separate GDC SNB Interactive suite

[DecisionNerd]

Objective

Integrate SNB Interactive independently without embedding its generator or driver in product code.

Requirements

• Pin spec, Datagen, driver, parameters, and dataset.
• Map supported operations to public GraphForge interfaces and declare gaps.
• Separate load, warmup, execution, and validation phases.

Acceptance criteria

• Tiny engineering scale validates mechanics and correctness.
• Completeness and unsupported-query policy are explicit.
• Results never masquerade as audited GDC certification.

BDD completion scenario

Given a pinned fixture
When supported operations run
Then results match the declared reference
And missing semantics are reported, not skipped.

Remaining completion evidence (2026-09-04)

Reopened after independent verification against main 905f2c5d: the existing suite does not yet execute the trusted live public GraphForge path proposed in #1084. Static/reference replay alone does not establish the public-path execution required above. Complete and review existing PR #1084, then verify the cumulative suite against every original acceptance criterion, including explicit unsupported semantics and truthful provenance/resource evidence. This note does not reduce workload coverage or turn a bounded live example into a full-suite claim. #952 remains the M11 completion gate.