Evaluator results: preserve legacy keys via safe projections

Observation (2026-09-06, source: ender-inference COR-4069 / PR #144): adding privacy-safe evaluator-v2 evidence must not replace legacy nodes and evaluation_findings, because dashboard consumers depend on their shapes. Build new allow-listed node_results/selected_evaluation_findings, retain sanitized legacy projections, and represent native findings with redacted durable node associations as explicitly unscoped rather than attributing them to a node. Full-batch analytics must be computed before result-page slicing; recommendations should remain correlation-only and mark tool-schema edits unavailable without compatible schema ownership.