Checkpoint: current Lumen state

pipeline/hash.ts

@@ -0,0 +1,26 @@
+/**
+ * SHA-256 helpers — Node crypto (pipeline build-time).
+ * Trace: ARCH 10.5, SPIKE-04 F-5, IMPLEMENTATION-CONTRACT.md §11
+ */
+import { createHash } from "node:crypto";
+import { canonicalJson } from "./canonical-json.js";
+
+export function sha256Hex(bytes: Uint8Array): string {
+  return createHash("sha256").update(bytes).digest("hex");
+}
+
+export function sha256HexOfString(str: string): string {
+  return sha256Hex(new TextEncoder().encode(str));
+}
+
+export function sha256HexOfJson(value: unknown): string {
+  return sha256HexOfString(canonicalJson(value));
+}
+
+export function bytesOfString(str: string): Uint8Array {
+  return new TextEncoder().encode(str);
+}
+
+export function bytesToString(bytes: Uint8Array): string {
+  return new TextDecoder().decode(bytes);
+}