Add LG PuriCare water purifier 1WPU4CIGCR__2 (stateless)

[tunarabuuu]

Sixth and last of the per-device-class splits from #111.

1WPU4CIGCR__2 — an AA..BB ThinQ2 water purifier (deviceType 103), driven through LG's capability API (the read map doubles as the write map). The sterilization reservation stays read-only: a time-only write moves the appliance's weekly day anchor and LG's schema can't preserve it.

Addressing your review notes from #111:

• stateless — no persistent history in rethink. State and the raw reservation are published straight from each frame. Dispense volumes arrive as per-report deltas, which the driver sums into a monotonic in-memory counter (reset to zero on restart) published as total_increasing, so HA does the accumulation exactly as it does for energy meters. The whole purifier-history-store module, the day-rollover/midnight timers, the persisted sterilization schedule, and the "last month count / last sterilize" entities are gone.
• processAABB — reads go through the base class's processAABB now (offsets need no whole-frame adjustment).
• time / KST — dropped entirely; the reservation is published raw as month.day HH:MM, no timezone conversion.
• logging utility — console.warn calls now use log(...).
• header comment / test-only helpers — trimmed the header, and the test file is rewritten around the stateless behaviour.

The driver drops from ~1030 lines to ~330. All labels are English. npm test passes; tsc clean.

This completes the split; I'll close #111 and link all six here.