hal speaks pver 5: preimages prove their size, and fees round up as one

0.6.0 servers require the new hashlock clauses (OP_SIZE 32 guard) for
Lightning and rounds. New policies/transitions carry the v1 scripts and
type bytes; _v0 variants keep old vtxos reconstructing and exiting.
The retired third-party HTLC policy is dropped (upstream took 0x08).

Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01M5kFodm9azZJVTQxnkDdKe

1 files changed, 3 insertions, 2 deletions

diff --git a/src/ark/validate.js b/src/ark/validate.js
index d09f6ec..fae3465 100644
--- a/src/ark/validate.js
+++ b/src/ark/validate.js
@@ -77,10 +77,11 @@ export async function validateVtxo(vtxo, { serverPubkey, chain, expectPubkeys, a
     const sig = hex.decode(t.signature);
 
     let msg, key;
-    if (t.type === 'hashLockedCosigned') {
+    if (t.type === 'hashLockedCosigned' || t.type === 'hashLockedCosigned_v0') {
       // script-spend through the unlock clause; signed by the raw agg key
       const hash = t.unlock.hash ? hex.decode(t.unlock.hash) : sha256(hex.decode(t.unlock.preimage));
-      const tp = harkLeafTaproot(hex.decode(t.userPubkey), serverPubkey, vtxo.expiryHeight, hash);
+      const gen = t.type === 'hashLockedCosigned' ? 1 : 0;
+      const tp = harkLeafTaproot(hex.decode(t.userPubkey), serverPubkey, vtxo.expiryHeight, hash, gen);
       msg = taprootScriptSighash(tx, [prevout], tapLeafHash(tp.unlockScript));
       key = tp.internalXOnly;
       if (!t.unlock.preimage) fail(`transition ${i} has no unlock preimage`);