`@Next/Env`: `LoadEnvConfig` With `ForceReload` Wipes `Process.Env` Before Reading, Breaking FIFO-Mounted `.Env` Files

The function `loadEnvConfig` in `packages/next-env/index.ts` calls `replaceProcessEnv(initialEnv)` before attempting to read the `.env` files. `initialEnv` is a snapshot taken before the first load and does not contain any `.env` values. If the subsequent read fails or yields no data (as with a drained FIFO), the environment remains reset, and errors/empty reads are silently ignored.

1. Clone https://github.com/jhb-dev/next-env-fifo-repro 2. Run `npm install` 3. Run `npm run repro` The script creates a FIFO named `.env` that serves its contents once then empty. It calls `loadEnvConfig` twice: normally, then with `forceReload: true`. The output shows the value loads initially but is undefined after the forced reload.

The change alters the order of environment reset. In scenarios where a user intentionally replaces a `.env` file with an empty one and expects to clear variables during a forced reload, this fix would keep the old variables. This may be surprising. Additionally, the guard relies on `previousEnv.parsedEnv` being non-empty; if the previous load was also empty, the reset still occurs. Rollback: To revert, restore the original code by moving `replaceProcessEnv(initialEnv)` back to its original position before the reading loop. Test thoroughly with multiple environment files and different file-system types to ensure no regression.