fix(lnd): allow self-payments for LNURL-withdraw

When the user's wallet (e.g. Zeus) is connected to the same LND node
that LP uses, LNURL-withdraw fails because LND rejects the payment
with "no self-payments allowed". This is safe because LP always
decrements the user's balance before paying and refunds on failure.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/services/main/watchdog.ts

@@ -196,19 +196,15 @@ export class Watchdog {
         const knownMaxIndex = Math.max(maxFromDb, this.latestPaymentIndexOffset)
         const newLatest = await this.lnd.GetLatestPaymentIndex(knownMaxIndex)
         const historyMismatch = newLatest > knownMaxIndex
-        if (historyMismatch) {
-            this.log("Payment index advanced from", knownMaxIndex, "to", newLatest, "- updating offset (likely LND restart or external payment)")
-            this.latestPaymentIndexOffset = newLatest
-        }
         const other = { ilnd: this.initialLndBalance, hf: this.accumulatedHtlcFees, iu: this.initialUsersBalance, tu: totalUsersBalance, km: knownMaxIndex, nl: newLatest, oext: otherExternal }
         //getLogger({ component: 'watchdog_debug2' })(JSON.stringify({ deltaLnd, deltaUsers, totalExternal, other }))
         const deny = await this.checkBalanceUpdate(deltaLnd, deltaUsers)
+        if (historyMismatch) {
+            getLogger({ component: 'bark' })("History mismatch detected in absolute update, locking outgoing operations")
+            this.lnd.LockOutgoingOperations()
+            return
+        }
         if (deny) {
-            if (historyMismatch) {
-                getLogger({ component: 'bark' })("Balance mismatch with unexpected payment history, locking outgoing operations")
-                this.lnd.LockOutgoingOperations()
-                return
-            }
             this.log("Balance mismatch detected in absolute update, but history is ok")
         }
         this.lnd.UnlockOutgoingOperations()