Add benchmark CLI

[timneutkens]

Summary

• add a unified CLI for selecting frameworks, packages, benchmark measurements, and run counts
• support dry runs, version overrides, dependency reuse, and benchmark discovery
• document local benchmark usage and expose the command from the workspace root

Validation

• pnpm exec prettier --check on all changed files
• pnpm --filter @framework-tracker/stats-generator lint
• pnpm --filter @framework-tracker/stats-generator type-check
• pnpm benchmark --help
• pnpm benchmark --list

[43081j]

can this use node's built in parseArgs instead?

[AlexanderKaran]

@timneutkens Looks great.

Can we just address James comment about and we can get this merged.