Read/write small text files and upload/download large or binary files on a Runloop devbox

Documented steps

1. For small UTF-8 text files use file.write: Python `await devbox.file.write(file_path="/home/user/main.py", contents='print("Hello, World!")')`; TypeScript `await devbox.file.write({ file_path: '/home/user/main.py', contents: '...' })`. Relative paths resolve to the user's home directory.
2. Read small UTF-8 files with file.read: Python `contents = await devbox.file.read(file_path="/home/user/test_results.txt")`; TypeScript `await devbox.file.read({ file_path: '...' })`.
3. For large or binary files use file.upload (accepts a stream/binary handle): Python `file = open('large_data.txt','rb'); await devbox.file.upload(file_path="/home/user/large_data.txt", file=file)`; TypeScript passes `fs.createReadStream(...)` as `file`.
4. Download large/binary files with file.download: Python `contents = await devbox.file.download(file_path="/home/user/large_data.txt")`; TypeScript `await devbox.file.download({ path: '/home/user/large_data.txt' })`.
5. Use absolute file paths to avoid ambiguity, and prefer async clients to avoid request timeouts on large transfers.
6. Docs: https://docs.runloop.ai/docs/devboxes/files