Epic: Establish the unified Django platform architecture

Normative spec: 01 — Platform architecture

Outcome

Deliver one deployable Django application with explicit domain boundaries, shared application services, PostgreSQL-backed state, durable background work, safe configuration, health behavior, and separate web/worker processes.

Boundaries

This epic coordinates architecture work; domain behavior remains in the content, course, event/email, Studio/API, security, infrastructure, and verification epics. Do not introduce microservices or a client-side SPA.

Epic completion gate

• All platform-foundation child issues are closed.
• Public, Studio, API, and job adapters share services rather than duplicating mutations.
• Failure-degradation and configuration contracts from the normative spec are verified.
• Every Python workflow is reproducible through locked uv commands.

Dependencies

Starts with #1. Child issue checklist will be maintained as implementation issues are filed.

Child issues

• #1
• #31

Start with the normative specification in _docs/specs/01-platform-architecture.md and review the completion gate for this epic. Then inspect child issues #1 and #31 and the implementation issues added to the checklist. Done means the platform-foundation child issues are closed and the listed architecture, configuration, degradation, service-sharing, and reproducibility contracts are verified.