Benchmark and optimize hot paths in lexer, parser, evaluator, and renderer

[Matographo]

Summary

Measure cold and warm performance, identify bottlenecks, and optimize the most important execution paths.

Why

Performance is a defining project requirement and needs explicit benchmark-driven optimization work.

Acceptance Criteria

• Benchmarks are reproducible
• Hot-path optimizations are documented
• Improvements are demonstrated against a baseline

Dependencies

• Depends on Implement a simple high-performance lexer #16
• Depends on Implement the core renderer for strings and single files #22
• Depends on Implement in-memory caching for parsed templates and include dependencies #24
• Depends on Build the automated test matrix for precedence, includes, control flow, and cache correctness #27