hexToInt4 parses a 32-char hex string (IPv6) into four uint32 values. The kernel stores IPv6 as 4 x uint32 in little-endian format. Returns (w0, w1, w2, w3) corresponding to bytes 0-3, 4-7, 8-11, 12-15.
(h string)
Source from the content-addressed store, hash-verified