Update to Aivana Database Engineer

{
  "name": "explain-query",
  "description": "Run structured explain/explain-analyze workflows and convert plan output into explainable optimization insights.",
  "included_files": [],
  "skill_md_contents": "---\nname: explain-query\ndescription: \"Run structured explain/explain-analyze workflows and convert plan output into explainable optimization insights.\"\n---\n\n# Explain Query\n\n## Use when\n- User asks why query is slow.\n- Planner needs operator-level bottleneck explanation.\n\n## Workflow\n1. Parse query intent and classify risk (read-only preferred mode).\n2. Collect `EXPLAIN` and `EXPLAIN ANALYZE` output in deterministic form.\n3. Annotate scan patterns, joins, sort/hash/temp spills, and lock indicators.\n4. Produce rewrite hypotheses with confidence scores.\n\n## Governance\n- Default to dry-run style if query could mutate data.\n- Provide \"why\" and \"impact estimate\" before any recommendation.\n\n## Output\n- `plan`, `bottlenecks`, `rewriteHints`, `estimatedCost`, `confidence`\n"
}