Dynamically load home dir when using NEAR localnet

When running the app against a local near blockchain using NEAR localnet, `near-api-js` needs a path to the near key file on your computer. This means the app needs to know what the home directory is when it's in this mode.

Tasks:

- [ ] Find a way to dynamically load the `$HOME` environment variable into the development server when running in localnet mode.
- [ ] Uncomment the [localnet config](https://github.com/bafnetwork/baf-badges/blob/5dcb954c59c9f438578bdf28611b34dbf8e262e3/config/nearConfig.ts#L37) and add it to `getConfig`

Start with config/nearConfig.ts and the getConfig entry point, then inspect how the development server receives environment variables in localnet mode. The work is done when the localnet configuration is enabled and the server supplies the computer's $HOME path so near-api-js can find the NEAR key file.

Written by the indexing model from the issue text.