Rework import_tickets.py from the retired JSON `latest.json` model to the new
hourly full-snapshot CSV export. Strictly INC (CRQ out of scope).
- Ingest the newest automations/inc/<EAT-timestamp>.csv; skip-if-unchanged by
comparing S3 ETag to tickets.import_meta.metadata.source_etag.
- Upsert on ticket_id (PK; no dups, never delete -> closure history accrues).
No truncate. On success, move processed files to automations/inc/processed/.
- Clean at ingest: drop is_alarm=true + the "EXPORT STOPPED..." sentinel; drop
week_*, source_s3_*/source_snapshot_id, department/source_type; lowercase
region, uppercase raw_status; keep service_type + bucket.
- Force path-style S3 addressing; --inc-csv for local dev; --from-bucket for cron.
- Add migrations/02 (import_meta + freshness); refresh README/.env.example/docs.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>