Establish the TypeScript API backend foundation

## Outcome

GovTool has a production-ready TypeScript backend foundation for the new governance APIs and platform services.

## Scope

- Select and document the runtime and service architecture
- Define configuration, dependency injection, errors, logging, health, and observability conventions
- Establish API versioning and generated documentation
- Provide build, test, container, migration, and deployment foundations

## Acceptance criteria

- [ ] Scope is decomposed into independently deliverable child issues.
- [ ] Architecture and API decisions are linked from this issue.
- [ ] Test, documentation, observability, rollout, and failure behavior are defined where applicable.
- [ ] Epic exit criteria are verified before closure.

## Planning note

This is a 2026 GovTool revamp work item. Its child features and tasks should be added as the scope is refined.