**Overall Verdict:** Strong Accept — The submission is complete, internally consistent, professionally scoped, and supports an objective end-to-end implementation and evaluation workflow.

**Completeness Check:**
- Instruction: Complete — The PDE, coefficients, boundary and initial data, discretization, solver interface, ADI constraints, mesh sequence, artifacts, and acceptance thresholds are explicit.
- Inputs: Complete — The specification and runtime materials provide all numerical parameters, call signatures, dependency versions, and staging conventions needed to implement the solver.
- Toolchain: Complete — Python 3.11–3.13 with pinned NumPy 2.4.6 and SciPy 1.17.1 is legally obtainable on Linux; the wrapper provides a locked-environment path and a clearly disclosed fallback.
- Reference output: Complete — The reference solver, JSON results, and eight-array NPZ are present and coherent. The arrays use little-endian float64 with the required `(5,)` and `(161,161)` shapes; the grid, analytic solution, error surface, boundary values, convergence errors, and sidecar values agree numerically.
- Rubric: Complete — The grader defines unambiguous 1.0, 0.5, and 0.0 outcomes and checks schema, convergence, hidden-instance generality, provenance, pointwise field reproduction, dependency restrictions, causal use of solves, and ADI solve structure.

**File and Task Reachability:**
Attachment classification: reachable. Task classification: reachable. The inspected files were `problem_spec.md`, `python.sh`, `pyproject.toml`, `uv.lock`, `reference_arrays.npz`, `adi_solver.py`, `results.json`, `EVALUATION.md`, `scheme_survey.py`, and `grade.py`; no manifested attachment was left unreviewed. All byte counts matched the manifest. The NPZ was valid, unencrypted, free of unsafe paths, and passed container integrity checks. Its reported errors decrease by approximately 208.7×, have fitted order 1.929, and match the exact finest-grid error.

Uploaded programs were inspected statically and not executed, as required by the safety policy. This did not prevent verification of their structure or the numerical artifacts. Solver-visible inputs are clearly separated from protected reference and evaluator assets. A contributor can implement the solver using the pinned environment, emit the three required outputs, and be evaluated through deterministic public-grid checks plus protected hidden-instance and causal-sweep checks on an ordinary single machine.

License keys, accounts, tokens, and other credentials are not required from the contributor. Confidential, proprietary, or internal material may be evaluated as submitted evidence without requiring additional disclosure.

**Special Screening:**
None. No affirmative evidence supports an `ai_synthetic`, `public_benchmark`, or `synthetic_defect_fixture` label. Public identifiability was not externally verified because approved search was unavailable.

**Recommended Changes:**
The submission already provides a rigorous implementation contract, truthful reference artifacts, and unusually thorough anti-shortcut evaluation coverage. No changes are required.