v3.0.0 — independent per-item cooks

Run multiple items on one grill with staggered, independent timelines. Each probe gets its own On/Wrap/Sauce/Flip/Done timeline, start clock, elapsed, and target; the grill temp/target and notes stay shared. Per-item markers on the chart, per-item editable logs. Update via HACS (offers 3.0.0), then reload. Upgrades v2 automatically (old shared events become grill notes).