Export calculateThumbprint from @hellocoop/httpsig

Expose the RFC 7638 JWK thumbprint function as a public API so consumers
don't need to implement their own (which led to bugs with missing y
parameter for EC keys).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dickhardt

httpsig/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@hellocoop/httpsig",
-    "version": "1.4.0",
+    "version": "1.5.0",
     "description": "HTTP Message Signatures (RFC 9421) with Signature-Key header support",
     "repository": {
         "type": "git",

httpsig/src/index.ts

@@ -23,6 +23,8 @@ export {
 export { generateKeyPair } from './utils/crypto.js'
 export type { GenerateKeyPairOptions, KeyPair } from './utils/crypto.js'
 
+export { calculateThumbprint } from './utils/thumbprint.js'
+
 export type {
     HttpSigFetchOptions,
     SignatureKeyType,