Implement simple import for quickjs

[Perlmint]

Summary

Add local module import support to the QuickJS executor. Workflow scripts can now import from sibling TypeScript/JavaScript files, enabling shared utilities across workflows.

Non-local specifiers (npm packages, URLs) and dynamic import() calls are not supported. The executor returns an error for these cases so callers can fall back to a Node.js-based runner.

Changes

• Introduce ModuleResolver that resolves transitive local dependencies, strips TypeScript, and converts export declarations to var so exported names persist as globals across sequential eval() calls
• Cache type-stripped modules within a single build run — each file is processed only once even when multiple workflows share the same dependency
• Remove the previous approach of forcibly injecting the runtime as a bundled prefix; the runtime is now just another module loaded through the resolver
• Add workflows/lib/common.ts as a working example: shared step helpers imported by update-workflows.ts and vitepress.ts

Checklist

• cargo test --all-features passes
• cargo clippy --all-targets --all-features -- -D warnings passes
• cargo fmt --all --check passes
• Updated documentation if needed
• Added tests for new functionality