R6.2 History import

Plan issue R6.2, phase 6 of the community-base unification plan.

Spec: docs/plan/phase-6.md, section R6.2, in DataTalksClub/community-base. Status is tracked in docs/plan/STATUS.md there, which stays the source of truth.

Depends on: R6.1. Do not start until every one of them is done in STATUS.md.

Process

This repository's AGENTS.md and docs/PROCESS.md govern this work. The plan says what to build and how to verify it; the repository process says how work is done here.

Spec

Repository: DataTalksClub/relay. Depends on: R6.1.

Read first

• ~/git/ai-shipping-labs/email_app/models/ (EmailLog, SesEvent, EmailCampaign,
  CampaignDelivery), email_app/services/email_log_history.py.

Steps

1. POST /api/import/messages (batch, idempotent on client_reference) creating historical
   transactional_messages rows with original timestamps, status, template key, recipient;
   POST /api/import/events for bounce, complaint, open and click events;
   POST /api/import/campaigns for campaigns and their recipient rows.
2. Contact history must show imported rows in order with the rest.
3. Management command import_history --from-json <file> for operators.

Verification

• Import a 10,000-row synthetic fixture twice -> second run creates zero rows; contact history
  for one address shows the imported messages.

First confirm R6.1 is marked done in docs/plan/STATUS.md, then read docs/plan/phase-6.md, AGENTS.md, and docs/PROCESS.md. Inspect the models in ~/git/ai-shipping-labs/email_app/models/ and email_app/services/email_log_history.py, then trace the import endpoints and management-command entry point. Done means both imports are idempotent, campaign and event data is present, and contact history shows imported messages after the 10,000-row fixture is run twice.