Expose boolean/deterministic scoring audit trail per path candidate

Current scoring is still float-based aggregates. For some compliance and auditable use cases, users want to know which criteria were discretely passed or failed by a given candidate path. Add:

• Option to output, per-candidate, a matrix or list of boolean pass/fail for each major scoring/validation criterion (input readiness, safety, domain fit, etc.)
• Ability to link these logs/outputs to final decision trace
• Configurable audit mode in PathScorer/GraphScoutAgent This will support production and regulatory needs where float scores or fuzzy explanations are insufficient.