Implement comprehensive test suite

[goruha]

Description

Create comprehensive test suite achieving 90% coverage for core modules and 80% for congenerics.

Tasks

• Create test structure mirroring module structure
• Implement tests for alphabet, order, intervals_chain, intervals_tuple, intervals_distribution
• Implement tests for characteristics
• Create congenerics test suite
• Add property-based tests using hypothesis
• Test valid inputs, edge cases, and invalid inputs
• Test all strategy variations
• Add integration tests for full pipelines
• Configure coverage reporting
• Set up CI/CD for automated testing

Dependencies

• Requires: All modules implemented

Related to

Phase 5: Testing and Performance

Acceptance Criteria

• Test coverage ≥ 90% for core modules
• Test coverage ≥ 80% for congenerics
• All edge cases covered
• Property-based tests verify invariants
• CI/CD runs tests automatically