- startup/client.lua now prompts on first run: asks if a dropper
is next to the computer, and if so, which side it's on
- Saves config to .dropper_config (JSON with dropperSide,
redstoneSide, enabled)
- Only launches dropperController if dropper is enabled
- dropperController.lua reads .dropper_config for its sides
instead of hardcoding 'back'
- Delete .client_setup to re-run the setup wizard
