Merge distillation-pipeline and shap-explainability to main

[William-Hill]

Summary

Prerequisite for the fine-tuning epic. Merge both feature branches to main so the epic branch starts from a clean baseline.

Tasks

• Merge feature/distillation-pipeline → main (training pipeline, school config, seed queries, model-client.ts)
• Merge feature/shap-explainability → main (SHAP computation, SHAP-aware enrich_with_llm, student API, feasibility report)
• Resolve any merge conflicts between the two branches
• Verify CI passes on main after both merges
• Create epic branch fine-tuning/student-explainability from updated main

Context

• feature/distillation-pipeline brings: training/ modules, schools/bishop-state/config.yaml, seed queries
• feature/shap-explainability brings: Step 10b SHAP computation, shap_explanations JSON column, safeParse helper

Acceptance Criteria

• Both branches merged to main without regressions
• Epic branch created and pushed to origin