refactor!: rewrite compiler workspace in TypeScript

[cayasde]

Summary

• refactor the compiler workspace from Rust/Cargo to TypeScript/npm
• replace the Rust frontend, HIR/type-checking, and lowering pipeline with a single Node-first implementation in src/index.ts
• port the regression suite to Vitest and preserve coverage for compilation output, parser/HIR behavior, type checking, imports, tuples, object methods, and stylesheet inheritance
• remove obsolete Rust crates, Cargo manifests, and Rust-only CI/release steps
• update docs, Makefile, gitignore, and GitHub workflows for the TypeScript toolchain

Why

• the project is centered on language tooling for UI-oriented source files, so moving to TypeScript puts the compiler in the same runtime and package ecosystem as the consumers most likely to embed it
• the Node ecosystem provides a much broader surface for parser tooling, editor integrations, bundlers, CLIs, language-server plumbing, browser-facing demos, and npm-based distribution than the current Rust setup
• TypeScript reduces the integration cost for downstream users that want to script compiler behavior, inspect IR, or compose Slynx with existing frontend build pipelines without introducing an FFI boundary or a separate Cargo toolchain
• the rewrite simplifies contributor onboarding because local setup, CI, release packaging, and test execution now all run through the same npm workflow instead of a multi-crate Rust workspace
• consolidating the pipeline into one TS package makes the codebase easier to evolve while preserving the tested language surface through the migrated regression suite

Validation

• npm run check
• npm test
• npm run build