Classify the WABT reader file-size boundary as a deterministic resource constraint with its input allowance. Give Go input-size refusals selected-input recovery rather than evidence-write advice. Preserve configuration and cleanup semantics.
Validation: 66 focused tests across four files including public CLI refusals, plus docs checks and five conformance tests. Sparse admission fixtures and version-only WABT stubs; no real WABT execution. Refs #4621, #4622