fix(sdk-coin-flrp): enhance toBroadcastFormat to include checksum

TICKET: WIN-8445

Author: mohd-kashif

modules/sdk-coin-flrp/src/lib/transaction.ts

@@ -231,9 +231,14 @@ export class Transaction extends BaseTransaction {
       return FlareUtils.bufferToHex(this._rawSignedBytes);
     }
     const unsignedTx = this._flareTransaction as UnsignedTx;
-    // Always include credentials in the output with checksum (matching avaxp behavior)
-    // This ensures unsigned transactions have empty signature slots for identification
-    return FlareUtils.bufferToHex(utils.addChecksum(unsignedTx.getSignedTx().toBytes()));
+    const signedTxBytes = unsignedTx.getSignedTx().toBytes();
+
+    // Both P-chain and C-chain transactions include checksum (matching avaxp behavior)
+    // avaxp P-chain: transaction.ts uses addChecksum() explicitly
+    // avaxp C-chain: deprecatedTransaction.ts uses Tx.toStringHex() which internally adds checksum
+    const rawTx = FlareUtils.bufferToHex(utils.addChecksum(signedTxBytes));
+    console.log('rawTx in toBroadcastFormat:', rawTx);
+    return rawTx;
   }
 
   toJson(): TxData {