Generated barrel re-exports use `export { Interface }` instead of `export type { Interface }`

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## Description

The generated barrel files (e.g. `renderer/app.ts`) re-export TypeScript interfaces as value exports instead of type-only exports. This breaks at runtime with esbuild/Vite since single-file transpilers strip types from source modules, making the named re-export unresolvable.

## Generated code (`renderer/app.ts`)

```ts
export * from '../common/app.js';
export { AppService, IAppServiceRenderer } from '../_internal/renderer/app.js';
```

`IAppServiceRenderer` is a TypeScript interface. In `_internal/renderer/app.ts`, it's imported as `import type { IAppServiceRenderer }` — so esbuild strips it during transpilation. The barrel re-export then fails at runtime:

```
Uncaught SyntaxError: The requested module '/_internal/renderer/app.ts'
does not provide an export named 'IAppServiceRenderer'
```

## Expected

Type-only names should use `export type`:

```ts
export { AppService } from '../_internal/renderer/app.js';
export type { IAppServiceRenderer } from '../_internal/renderer/app.js';
```

## Notes

- This is the same class of issue that TypeScript's `isolatedModules` flag warns about — re-exporting a type as a value requires cross-file analysis that single-file transpilers (esbuild, SWC) don't perform.
- Workaround: post-process the generated barrel files to split value and type re-exports.

## Environment

- `@marshallofsound/ipc`: 2.6.2
- Electron 40, Vite 7, TypeScript 6

Start with the generated renderer/app.ts and compare its exports with the type-only import in _internal/renderer/app.ts, then trace back to the generator that produced the barrel. Verify the generated output with an esbuild or Vite single-file transpilation flow; done means interfaces use type-only re-exports and no runtime named-export error occurs.

Written by the indexing model from the issue text.