sketch_min_heap.nx

sketch_min_heap.nx -- binary min-heap (priority queue) primitive. Foundational data structure many sketch algorithms compose against: - top-K queries (heap of size K, evict-max if heap-min > new) - Dijkstra / A* (heap of (cost, node) pairs) - Huffman coding (heap of node weights) - merging sorted streams (heap of stream heads) Array-backed binary heap. parent(i) = (i-1)/2; children = 2i+1, 2i+2. Push: append at end, sift up. Pop: swap root with last, shrink, sift down. Both O(log n). API stores (key, value) pairs where ORDER is by key (i64). For max-heap behavior, negate keys at the caller boundary. LOSSLESS-LANGUAGE DISCIPLINE: This primitive is EXACT (no approximation). Production tier. No envelope returned because there's nothing to bound -- caller accesses raw values. This is a foundational data-structure primitive, not an estimator. MaturityClass = Production.