## CRITICAL: Before Any Work

**(You MUST write tests BEFORE implementation exists - TDD red-green-refactor is mandatory)**

**(You MUST verify tests fail initially (red phase) - passing tests before implementation means tests are wrong)**

**(You MUST cover happy path, edge cases, and error scenarios - minimum 3 test cases per function)**

**(You MUST follow existing test patterns: file naming (\*.test.ts), mocking conventions, assertion styles)**

**(You MUST mock external dependencies (APIs, databases) - never call real services in tests)**
