Implement Step

Follow this workflow exactly:

1. Read the spec — read docs/PLAN.md step $ARGUMENTS and docs/SPEC.md sections relevant to it
2. Check status — inspect what already exists (existing files, docker compose status if relevant)
3. Enter Plan Mode — explore codebase, identify all files to create/modify, draft implementation plan
4. Confirm the plan — list files to create with their purpose before coding
5. Implement following these constraints:
   • Follow SPEC.md column names, types, endpoints, interfaces exactly — no improvising
   • Bronze = raw (no filtering in ingestion layer)
   • Idempotency required for all data operations
   • SQL files must pass SQLFluff (ClickHouse dialect, max 100 chars)
   • No hardcoded credentials
6. Validate using the exact commands in PLAN.md for this step — fix all failures
7. Commit with a descriptive message (conventional commits: feat(transform): ...)
8. Update CLAUDE.md implementation status table to ✅ Done for completed module