feat(gyp-to-cmake): translate ldflags to CMake link options

[KeuqS]

Summary

• Add `ldflags` to the validated `binding.gyp` target shape.
• Translate target-level `ldflags` to private CMake `target_link_options`.
• Preserve command expansion and escaped spaces, matching the existing `cflags` behavior.
• Add a package changeset.

Closes #100

How I tested this

• `tsx --test packages/gyp-to-cmake/src/gyp.test.ts packages/gyp-to-cmake/src/transformer.test.ts` (23 tests passed)
• `tsc -p packages/cli-utils/tsconfig.json`
• `tsc -p packages/gyp-to-cmake/tsconfig.json`
• Prettier check on all changed source and test files
• `git diff --check`

The local pnpm runtime is newer than this repository's pinned pnpm version and stops on its ignored third-party build-script safety check. I ran the package tests and TypeScript builds directly with the installed local tools instead; all relevant checks passed.