Need better `eject`

### Prerequisites

- [X] I have written a descriptive issue title
- [X] I have searched existing issues to ensure the feature has not already been requested

### 🚀 Feature Proposal

- [ ] it's unintuitive (for me at least) to have to imperatively declare `--esm` to `fastify eject` when using js/esm combination.
Like, when I'm already cd-ed into the dir, and eject is using `process.cwd()`, meaning it can also lookup pkg json and see what's there.
- [ ] other point is that scripts stay bound to CLI, I expect to have scripts overwritten to something like `"start" : "node server.js"` | `"dev" : "node --watch server.js"` at least in js case.

- [ ] bonus points if CLI would have removed itself from dependencies, and dumped that test helper into tests directory

### Motivation

I don't have to massage the generated project too much after `eject`

### Example

_No response_