Add query.self() returning one-shot self state (pos/health/food/heldItem/gameMode/isRaining/timeOfDay), add query.snapshot(range) returning combined self/inventory/nearby snapshot with counts/summary/emptySlots/totalStacks and blocks/entities/ores within range, add inventory.count(name)/has(name, atLeast)/summary() helpers for item queries, register query.self/snapshot as readonly functions in JavaScriptPlanner sandbox