/media/mmcsd-0-0    -- first partition
  /media/mmcsd-0-1    -- second partition
  ...
The partition(s) should be pre-formatted as FAT32.
Note the Script node must set: .setProcessor(dai.ProcessorType.LEON_CSS)

- displays an uncompressed preview stream of RGB camera at 640x360
- creates a HTTP server listing all files on the first partition of the SDcard
- when `C` is pressed, saves a 12MP JPEG capture to SDcard, file names starting from 1000.jpg

No file handles should be left opened for unmount to succeed, not even `os.chdir('/media/mmcsd-0-0')`.
Anyway, a `sync()` is attempted first