Configure NODE_OPTIONS environment variable on amplify hosting runtime to use node option --enable-source-maps

### Before opening, please confirm:

- [x] I have checked to see if my question is addressed in the [FAQ](https://github.com/aws-amplify/amplify-hosting/blob/master/FAQ.md).
- [x] I have [searched for duplicate or closed issues](https://github.com/aws-amplify/amplify-hosting/issues?q=is%3Aissue+).
- [x] I have removed any sensitive information from my code snippets and submission.

### Amplify Hosting feature

Environment variables

### Is your feature request related to a problem? Please describe:

#### background

Nodejs has a feature to output logs with source map, showing the stacktrace of source code lines like:
```
Error [SomeError]: Request failed with status code 400
at async c (webpack://some/pre/compiled/source/code/file.ts:51:30)
at async l (webpack://some/pre/compiled/source/code/file.ts:122:19)
```
instead of showing the stacktrace of transpiled & minified source code lines like:
```
Error [SomeError]: Request failed with status code 400
at eP (.next/server/chunks/850.js:21:59036)
at async c (.next/server/chunks/847.js:1:13619)
```

The feature can be turned on if these conditions are met:

**compile the source code with source map**

For example, next.js can compile with source map with the following config:

```next.config.js
const nextConfig = {
// ...

webpack: (config, {isServer}) => {
if (isServer) {
config.devtool = 'source-map'
}
return config
},
}
```
ref: https://www.highlight.io/blog/lw5-next-js-server-sourcemaps

**set NODE_OPTIONS=--enable-source-maps to launch nodejs**

To use source map for server side logging, at this time, the `--enable-source-maps` is needed as the launch option of nodejs.
https://nodejs.org/dist/latest-v22.x/docs/api/cli.html#cli_enable_source_maps

For example, the following next.js package.json can output logs with real source code lines:

```json
{
"scripts": {
"dev": "next dev",
"build": "next build",
"start": "NODE_OPTIONS=--enable-source-maps next start",
}
// other configs are omitted
}
```

#### problem

The amplify hosting service ignores the `NODE_OPTIONS` runtime environment.

I did the following things:

**adding `NODE_OPTIONS=--enable-source-maps` to the package.json file** does not take effect. Amplify just ignores it.

```json
{
"scripts": {
"dev": "next dev",
"build": "next build",
"start": "NODE_OPTIONS=--enable-source-maps next start",
}
// other configs are omitted
}
```

**adding `NODE_OPTIONS=--enable-source-maps` to the.env.production while building the source** does not take effect. Amplify just ignores it.

```yml
version: 1
applications:
frontend:
phases:
build:
commands:
- echo 'NODE_OPTIONS=--enable-source-maps' >> .env.production
- yarn build
artifacts:
baseDirectory: .next
files:
- '**/*'
```

### Describe how you'd like this feature to work

I'd like to set (OR append) NODE_OPTIONS option for the amplify hosting runtime.

The feature might look like changing amplify.yml spec as:

```yml
version: 1
applications:
frontend:
phases:
build:
commands:
- (omit)
runtime_node_options:
- '--enable-source-maps'
artifacts:
baseDirectory: .next
files:
- '**/*'
```
But I'd appreciate if the feature is implemented in any kinds of ways.

Start by reviewing the proposed amplify.yml runtime_node_options configuration alongside package.json, .env.production, and next.config.js. Trace how Amplify launches the Node.js runtime and determine how NODE_OPTIONS can be set or appended there. Done means --enable-source-maps is honored at runtime and server logs show source-mapped lines for a configured Next.js deployment.

Written by the indexing model from the issue text.