Burner: on-chain ref = burn id; recognise already-mined burns from CreditsConsumed and hold in-flight sends, so a lost RPC response can never double-burn

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

burner.js

@@ -37,6 +37,14 @@ async function setup() {
   } catch (e) { state.lastError = 'engineSigner read: ' + e.message; }
 }
 function refToBytes32(ref) { return ethers.zeroPadBytes(ethers.toUtf8Bytes(String(ref || '').slice(0, 32)), 32); }
+// the on-chain ref IS the burn id, so a burn that already mined can always be recognised
+// from its CreditsConsumed event, even when the RPC lost the response (a lost response
+// double-burned member #5's campaign 30 on 2026-09-10)
+function alreadyMined(b) {
+  const want = refToBytes32(b.id).toLowerCase();
+  const hit = chain.recentEvents(1e9).find(e => e.type === 'CreditsConsumed' && e.memberId === Number(b.memberId) && String(e.ref || '').toLowerCase() === want);
+  return hit ? hit.tx : null;
+}
 
 async function tick() {
   if (!state.enabled || state.mismatch || running || !ethers) return { burned: 0 };
@@ -53,15 +61,20 @@ async function tick() {
       try {
         // Polygon nodes reject low priority fees and some public RPCs answer fee
         // queries with 500s: set the fees ourselves from the server's estimate
+        const mined = alreadyMined(b);
+        if (mined) { await ads.markBurned(b.id, mined); burned += 1; state.burned += 1; continue; }
+        state.inflight = state.inflight || {};
+        if (state.inflight[b.id] && Date.now() - state.inflight[b.id] < 10 * 60000) continue; // sent recently, answer lost: wait for the event
         // dry-run first: a revert here (usually "Insufficient credits", the member's on-chain
         // balance is below what the engine metered) costs no gas and is left for the admin
-        try { await ctr.consume.staticCall(Number(b.memberId), 0, BigInt(b.amount), refToBytes32(b.ref)); }
+        try { await ctr.consume.staticCall(Number(b.memberId), 0, BigInt(b.amount), refToBytes32(b.id)); }
         catch (e) { state.skipped[b.id] = String(e.reason || e.shortMessage || e.message).slice(0, 120); continue; }
         const g = await chain.suggestedFees();
         const overrides = { gasLimit: 120000n, maxPriorityFeePerGas: BigInt(g.maxPriorityFeePerGas), maxFeePerGas: BigInt(g.maxFeePerGas) };
-        const tx = await ctr.consume(Number(b.memberId), 0, BigInt(b.amount), refToBytes32(b.ref), overrides);
+        state.inflight[b.id] = Date.now();
+        const tx = await ctr.consume(Number(b.memberId), 0, BigInt(b.amount), refToBytes32(b.id), overrides);
         const rc = await tx.wait(1);
-        if (rc && rc.status === 1) { await ads.markBurned(b.id, tx.hash); burned += 1; state.burned += 1; state.lastTx = tx.hash; state.lastError = null; }
+        if (rc && rc.status === 1) { await ads.markBurned(b.id, tx.hash); delete state.inflight[b.id]; burned += 1; state.burned += 1; state.lastTx = tx.hash; state.lastError = null; }
         else { state.lastError = 'consume reverted for burn ' + b.id; break; }
       } catch (e) {
         state.lastError = 'burn ' + b.id + ': ' + String(e.shortMessage || e.message).slice(0, 160);