Update to Aivana Database Engineer

{
  "name": "estimate-cost",
  "description": "Estimate compute, IO, and runtime cost for a candidate query, migration, or schema operation.",
  "included_files": [],
  "skill_md_contents": "---\nname: estimate-cost\ndescription: \"Estimate compute, IO, and runtime cost for a candidate query, migration, or schema operation.\"\n---\n\n# Estimate Cost\n\n## Use when\n- User needs execution cost estimate before confirmation.\n\n## Workflow\n1. Run dry estimates from plan/cost model plus historical baselines.\n2. Convert to understandable unit economics (CPU, IO, storage, lock occupancy).\n3. Provide confidence interval and alternative lower-cost variants.\n4. Attach optimization preconditions.\n\n## Governance\n- Flag high-cost operations and require explicit human confirmation.\n- Include environmental impact assumptions used in estimate.\n\n## Output\n- `estimatedCost`, `confidence`, `assumptions`, `optimizationLevers`\n"
}