Placement, not security.

k = snowflake
k = k XOR (k >> 33)
k = (k × 0xFF51AFD7ED558CCD) mod 2^64
k = k XOR (k >> 33)
hash32 = k mod 2^32

The constant carries Appleby's public-domain lineage, but the full finalizer's avalanche certificate does not transfer to a single round — so the distribution this series relies on is measured directly over snowflake-shaped inputs in the committed hash audit (bcs_hash_audit.out). Hosts without native unsigned 64-bit arithmetic emulate the multiply exactly: the BEAM uses bignums then masks, SQL splits 32-bit halves, JavaScript uses BigInt.

Seven runtimes — Elixir, Rust, C, TypeScript, wasm, Go, and SQL — reproduce 234878118 for the reference id in this repository's committed outputs. Adjacent inputs land far apart: one trailing bit between …864 and …865 separates 234878118 from 989747343.

hash32(274557032793636864)   = 234878118   ← the reference id
hash32(274557032793636865)   = 989747343   ← one trailing bit away
hash32(0)                    = 0
hash32(1)                    = 2466077478
hash32(4611686018427387904)  = 3201652940
hash32(9223372036854775807)  = 2186628710

Placement over the six committed vectors. Select a snowflake; a pure function replays the round, asserts the committed hash, and takes hash32 mod 2⁸ — the power-of-two modulus the contract bounds uniformity-critical consumers to (k ≤ 8). One function routes a CHAMP slot, a cache shard, and a hash partition; the routing table is retired.

Fairness across small or odd lane counts is constructed by round-robin assignment, never hashed; the 5-bit trie windows are clean at every level on the committed audit's evidence.

This is placement, not security. A non-cryptographic finalizer with no key is exactly the wrong tool wherever an adversary chooses inputs: the odd multiply and the xor-shift are both invertible, so truncation's 2³² preimages are the only veil. The contract states the edge and the manuscript repeats it — the round's virtue is spread, not secrecy.

Should a future measurement find pathology, the successor is hash32/v2 — the full two-round finalizer — behind a wire-version bump with a dual-placement migration window: placement evolution is a planned lane, not an emergency (content/contract.md §6).