[Konstantin (terrakok)]

Introduce a standalone Compose Multiplatform benchmarking project in compose/mpp/benchmarks to measure and compare startup and rendering performance across Compose and Kotlin versions.

• Support JVM, macOS ARM64, iOS ARM64 Simulator, JS, and WasmJS targets.
• Add reusable benchmark cases and four measurement modes: application startup, real UI frame timing, average offscreen rendering, and per-frame offscreen rendering.
• Add a command-line launcher with version, target, and browser matrices, configurable repetitions and timeouts, input validation, and process cleanup.
• Support benchmarking both published Compose versions and local core sources.
• Collect JSON results, logs, environment metadata, and test parameters, and generate interactive HTML reports with comparison charts, frame-time distributions, and links to raw results.
• Add manually triggered GitHub Actions workflows for JVM, iOS, and web benchmarks.
• Document how to run benchmarks and add new cases.

Testing

Smoke test from the repository root:

./run-benchmarks.sh --target jvm \
  --compose-version local \
  --tests LazyGrid \
  --modes startup realFrames averageFrame fps \
  --repeat 1 \
  --output-dir /tmp/compose-benchmark-results

Verify that the session directory contains an HTML report, JSON results, environment metadata, and logs.

Release Notes

N/A