Add JARVI3 DTL/SuperMath deterministic solver

[kyal102]

Summary

Adds a draft JARVI3 DTL/SuperMath solver integration for MathArena.

This PR includes:

• DTLSuperMathSolver, a deterministic routed solver that emits boxed answers for supported AIME 2026 lanes and \boxed{None} for unsupported cases.
• Vendored standalone DTL/SuperMath lane logic with no dependency on the JARVIS repository.
• A model config at configs/models/jarvi3/dtl-supermath.yaml with type: dtl_supermath.
• Runner wiring for the new solver type.

Claim Boundary

This is not an official leaderboard result. It is a reproducibility/audit integration candidate for maintainer review.

Public audit artifact:
https://github.com/kyal102/dtl-supermath-aime-2026-audit/releases/tag/dtl-supermath-aime-2026-audit-v1

Local audit result from that artifact:

• 14/30 routed answers correct
• 16/30 abstained
• 0 incorrect verified emissions
• 100% accuracy on answered routed cases

Validation

Validated locally in the source artifact before PR packaging:

• 24 passed across the MathArena-focused DTL/SuperMath adapter/proposer/solver/submission tests.

Validated in this MathArena fork branch:

• AST parse passed for src/matharena/solvers/dtl_supermath_solver.py and src/matharena/solvers/dtl_supermath_lanes.py.
• Deterministic lane smoke test returned 277 for aime_2026_01 and None for unsupported aime_2026_05.

Full runner.py bytecode compile was not run on this machine because MathArena declares requires-python = ">=3.12", while the available local Python is 3.11.9; Python 3.11 cannot parse existing upstream 3.12 f-string syntax in runner.py.

Maintainer Notes

Opening as a draft because the integration boundary may need adjustment. In particular, this deterministic lane solver is intentionally abstention-aware and competition-specific for the AIME 2026 audit artifact, rather than a general model baseline.