## ADDED Requirements

### Requirement: Test Directory Structure

The system SHALL organize tests into unit, integration, and system directories.

#### Scenario: Directory layout
- GIVEN the backend test suite
- THEN `apps/api/tests/` SHALL contain:
  - `unit/` - Pure logic tests with no external dependencies
  - `integration/` - API endpoint tests with database
  - `system/` - Full stack tests with external services

#### Scenario: Running selective tests
- GIVEN the test suite is organized
- WHEN running `pytest -m unit`
- THEN only unit tests SHALL execute
- AND WHEN running `pytest -m integration`
- THEN only integration tests SHALL execute

### Requirement: Test Markers

The system SHALL provide pytest markers for each test category.

#### Scenario: Marker registration
- GIVEN pytest configuration
- THEN `pyproject.toml` SHALL register markers:
  - `unit` - Fast tests with no external dependencies
  - `integration` - Tests with database and external services
  - `system` - End-to-end tests of the full stack

#### Scenario: Marker usage
- GIVEN a test file
- THEN unit tests SHALL be marked with `@pytest.mark.unit`
- AND integration tests SHALL be marked with `@pytest.mark.integration`
- AND system tests SHALL be marked with `@pytest.mark.system`