Create Backend Tests

Execution-phase PHPUnit implementation. Planning-phase: pm-unit-test-task-generator.

Harness discovery

Load {harness_root}/rules/backend-tests-rules.mdc and backend-rules.mdc when present. See references/backend-testing-architecture.md for layout, run contract, and bootstrap summary.

Phase 0 — Resolve or bootstrap backend test root

Before any test class code, locate the PHPUnit project or create minimal structure.

0.1 — Detect existing tests (brownfield)

Search {product_root} in this order:

1. backend/phpunit.xml
2. phpunit.xml at {product_root}/
3. tests/Unit/ or tests/Feature/ under the directory that contains composer.json with PHPUnit