add bench test

[yinjie-z]

💡 Issue Reference

Issue: #217

💻 What does this address?

This PR introduces performance optimizations and formal benchmarks for the sear library. It specifically targets the modernization of IRRSMO00, IRRSEQ00, and IRRSDL00 request generation.

📟 Implementation Details

CMake Infrastructure

• New Build Option: Introduced the SEAR_BUILD_BENCHMARKS toggle (Default: OFF) to prevent benchmark overhead in standard builds.
• Target bench_runner: Created a dedicated benchmark executable.
• Optimization: Forced -O3 optimization levels for the benchmark target to ensure timing reflects production-grade performance rather than unoptimized debug code.

CI/CD Integration

• Automated Benchmarking: Integrated a GitHub Workflow that triggers on every Pull Request.
• Insightful Reporting: Configured the workflow to parse benchmark results and automatically post a Performance Summary Table as a PR comment.
• Regression Tracking: Set a threshold to alert developers if a code change causes a significant increase in execution time or memory growth.

📋 Is there a test case?

cmake --preset linux-bench -DBUILD_SHARED_LIBS=on
cmake --build --preset linux-bench --target sear
cmake --build --preset linux-bench --target bench_runner

[yinjie-z]

The Benchmark Test workflow currently encounters a 403 Forbidden error (Resource not accessible by integration) when attempting to post the results table.

This is due to GitHub's security model for on: pull_request triggers originating from forks, which restricts the GITHUB_TOKEN to read-only access.

I am updating the workflow trigger to on: pull_request_target. This will allow the runner to access the base repository's write permissions safely, enabling the automated benchmark summary to be posted directly to this PR.

[EmmasBox]

LGTM