peripheral.wrap(selfName) can return nil on some turtles even when
connected. Switch to wrapping the remote chest and calling
chest.pullItems(selfName, slot) instead.
New miningTurtle.lua: sits on top of a cobble gen, continuously
digs down, and pushes items into networked chests via wired modem.
Features:
- Configurable mine interval, dump threshold, fuel slot
- Auto-dumps inventory when slots fill or timer expires
- Auto-refuels from designated fuel slot
- Remote reboot via SYSTEM_CHANNEL
- Stats display (mined, dumped, uptime, fuel)
- Persistent config in usr/config/inventory-manager/.miner_config
Also adds:
- startup/miner.lua: auto-update + launch script for standalone use
- .package: new 'Mining Turtle' role (option 4) in setup wizard
- autorun/startup.lua: detects .miner_config and launches miningTurtle
