Create performance benchmarking suite

[goruha]

Description

Implement comprehensive performance benchmarks to ensure no regressions and document performance characteristics.

Tasks

• Create benchmarks/ directory
• Set up pytest-benchmark
• Benchmark order → intervals_chain (all strategies)
• Benchmark intervals_chain → intervals_tuple (all strategies)
• Benchmark characteristic calculations on large sequences
• Compare old vs new API performance
• Compare core vs congenerics performance
• Set performance regression thresholds in CI
• Document performance characteristics in API reference
• Create performance comparison reports

Dependencies

• Requires: All modules implemented

Related to

Phase 5: Testing and Performance

Acceptance Criteria

• Benchmarks cover critical paths
• Performance regression detection in CI
• Congenerics shows measurable improvement over core
• Performance characteristics documented
• No regressions vs v0.0.22