fix: rework type-only export

[sxzz]

Summary

• track type-only exports per declaration module and propagate them through named re-exports and export-star chains
• restore type modifiers in final declaration chunks, including external export type * statements
• add regressions for type-only export chains and class re-exports

Closes #95

Tests

• pnpm exec vitest tests/index.test.ts --run -t "type-only"
• pnpm exec vitest tests/rollup-plugin-dts.test.ts --run
• pnpm run format
• pnpm run lint
• pnpm run typecheck

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/rolldown-plugin-dts@242

commit: 0d2efde