Move backend-result-type plan to docs/plans/completed/ with summary. Unified Result struct now used across all ML backends. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Automated fixes: interface{} → any, range-over-int, t.Context(), wg.Go(), strings.SplitSeq, strings.Builder, slices.Contains, maps helpers, min/max builtins. Co-Authored-By: Virgil <virgil@lethean.io>