Enable static files and configuration file support in YARP integration

### Is there an existing issue for this?

- [x] I have searched the existing issues

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

Aspire applications using YARP currently lack built-in support for serving static files. This limits the ability to expose static assets (e.g., HTML, JS, CSS, images) directly through the reverse proxy, which is a common requirement for dashboards, documentation, or lightweight frontends.

While the YARP container itself is capable of serving static files, Aspire does not yet expose a way to configure or enable this behavior within its application model. This creates a gap between what the underlying infrastructure can do and what Aspire makes accessible to developers.

Additionally, we face a related limitation in deployment scenarios: configuration via file is not currently supported. Specifically, WithContainerFiles and BindMount are not usable in deployment, which makes it difficult to provide static content or configuration assets in a portable and production-ready way.

### Describe the solution you'd like

- For configuration: we could translate the configuration file as a set of environment variables.
- For static files in general: we need a better support of "container files" or volumes in Aspire

### Additional context

_No response_