Research: strengthen CI tests with mutation testing and public interface behavior validation

[jonbaldie]

Summary

This PR adds comprehensive mutation testing and public interface behavior validation tests to strengthen the CI test suite.

Changes

• Created tests/mutation_behavior_test.ts with 31 new tests covering:
  • Mutation Testing: Tests designed to catch common code mutations (off-by-one errors, operator changes, boundary conditions)
  • Public API Behavior: Comprehensive testing of the queue HTTP API with edge cases and error conditions

Test Coverage

• Queue core logic (length, enqueue, dequeue, is_empty, peek)
• Manager operations (queue registration, isolation, state management)
• HTTP API endpoints (auth validation, data integrity, FIFO ordering, multiple queues)
• Edge cases (empty payloads, large payloads, special characters)

Results

• All 48 tests pass (9 auth + 31 new + 8 existing unit tests)
• Compile successful
• CI gates verified on rebased branch

Mutation Testing Benefits

Tests are designed to catch mutations such as:

• Off-by-one errors (length calculations)
• Operator mutations (== vs ===, < vs <=)
• Method mutations (shift vs pop, push vs unshift)
• Negation mutations (inverted boolean checks)
• State mutations (queue isolation, length tracking)

🤖 Generated with Claude Code