feat(action): add IIP-59 voter reward actions and BLS candidate fields

src/main/java/com/github/iotexproject/antenna/action/Envelop.java

@@ -48,6 +48,8 @@ public class Envelop {
     private StakeTransferOwnership stakeTransferOwnership;
     private CandidateRegister candidateRegister;
     private CandidateBasicInfo candidateUpdate;
+    private SetVoterRewardOptIn setVoterRewardOptIn;
+    private SetVoterRewardDestination setVoterRewardDestination;
     private StartSubChain startSubChain;
     private StopSubChain stopSubChain;
     private PutBlock putBlock;
@@ -141,6 +143,17 @@ public static Envelop deserialize(byte[] bytes) throws IllegalArgumentException
             if (core.getCandidateUpdate().toByteArray().length > 0) {
                 envelop.setCandidateUpdate(core.getCandidateUpdate());
             }
+            // hasX(), not toByteArray().length: SetVoterRewardOptIn carries no
+            // payload -- the sender is the delegate -- so it serializes to zero
+            // bytes and a length check drops it silently. The oneof's presence
+            // bit is the only thing that distinguishes "opt in" from "no action
+            // set at all".
+            if (core.hasSetVoterRewardOptIn()) {
+                envelop.setSetVoterRewardOptIn(core.getSetVoterRewardOptIn());
+            }
+            if (core.hasSetVoterRewardDestination()) {
+                envelop.setSetVoterRewardDestination(core.getSetVoterRewardDestination());
+            }
 
             return envelop;
         } catch (InvalidProtocolBufferException e) {
@@ -211,6 +224,12 @@ public ActionCore core() {
         if (candidateUpdate != null) {
             builder.setCandidateUpdate(candidateUpdate);
         }
+        if (setVoterRewardOptIn != null) {
+            builder.setSetVoterRewardOptIn(setVoterRewardOptIn);
+        }
+        if (setVoterRewardDestination != null) {
+            builder.setSetVoterRewardDestination(setVoterRewardDestination);
+        }
         if (startSubChain != null) {
             builder.setStartSubChain(startSubChain);
         }

src/main/java/com/github/iotexproject/antenna/action/method/SetVoterRewardDestinationMethod.java

@@ -0,0 +1,46 @@
+package com.github.iotexproject.antenna.action.method;
+
+import com.github.iotexproject.antenna.action.Envelop;
+import com.github.iotexproject.antenna.crypto.Bech32;
+import com.github.iotexproject.antenna.protocol.SetVoterRewardDestinationRequest;
+import com.github.iotexproject.antenna.rpc.RPCMethod;
+import com.github.iotexproject.grpc.types.Action;
+import com.github.iotexproject.grpc.types.SetVoterRewardDestination;
+import com.google.protobuf.ByteString;
+
+/**
+ * SetVoterRewardDestination method.
+ *
+ * <p>The protocol reads the recipient with address.FromBytes, so the io1...
+ * string is decoded to its 20 raw bytes here. Sending the bech32 text instead
+ * produces an action that signs and is then rejected on decode.
+ */
+public class SetVoterRewardDestinationMethod extends AbstractMethod {
+    private final SetVoterRewardDestinationRequest request;
+    private final Envelop envelop;
+
+    public SetVoterRewardDestinationMethod(RPCMethod client, SetVoterRewardDestinationRequest request) {
+        super(client, request.getAccount());
+        this.request = request;
+        this.envelop = baseEnvelop(request);
+    }
+
+    private SetVoterRewardDestination payload() {
+        byte[] dec = Bech32.decode(request.getRecipient()).data;
+        byte[] raw = Bech32.convertBits(dec, 0, dec.length, 5, 8, false);
+        return SetVoterRewardDestination.newBuilder()
+                .setRecipient(ByteString.copyFrom(raw))
+                .build();
+    }
+
+    @Override
+    public String execute() {
+        envelop.setSetVoterRewardDestination(payload());
+        return sendAction(envelop);
+    }
+
+    public Action signedAction() {
+        envelop.setSetVoterRewardDestination(payload());
+        return signAction(envelop).action();
+    }
+}

src/main/java/com/github/iotexproject/antenna/action/method/SetVoterRewardOptInMethod.java

@@ -0,0 +1,35 @@
+package com.github.iotexproject.antenna.action.method;
+
+import com.github.iotexproject.antenna.action.Envelop;
+import com.github.iotexproject.antenna.protocol.SetVoterRewardOptInRequest;
+import com.github.iotexproject.antenna.rpc.RPCMethod;
+import com.github.iotexproject.grpc.types.Action;
+import com.github.iotexproject.grpc.types.SetVoterRewardOptIn;
+
+/**
+ * SetVoterRewardOptIn method.
+ *
+ * <p>Opts the sending delegate into IIP-59 protocol-native voter reward
+ * distribution. The message is empty by design -- the sender is the delegate --
+ * so it must be set on the envelope explicitly rather than left to a
+ * "non-empty payload" check, which would drop it.
+ */
+public class SetVoterRewardOptInMethod extends AbstractMethod {
+    private final Envelop envelop;
+
+    public SetVoterRewardOptInMethod(RPCMethod client, SetVoterRewardOptInRequest request) {
+        super(client, request.getAccount());
+        this.envelop = baseEnvelop(request);
+    }
+
+    @Override
+    public String execute() {
+        envelop.setSetVoterRewardOptIn(SetVoterRewardOptIn.newBuilder().build());
+        return sendAction(envelop);
+    }
+
+    public Action signedAction() {
+        envelop.setSetVoterRewardOptIn(SetVoterRewardOptIn.newBuilder().build());
+        return signAction(envelop).action();
+    }
+}

src/main/java/com/github/iotexproject/antenna/protocol/SetVoterRewardDestinationRequest.java

@@ -0,0 +1,19 @@
+package com.github.iotexproject.antenna.protocol;
+
+import lombok.Data;
+
+/**
+ * setVoterRewardDestination request.
+ *
+ * <p>Redirects the sender's own IIP-59 voter rewards. Passing the sender's own
+ * address clears the override.
+ *
+ * <p>The protocol resolves the destination live at drain time rather than
+ * snapshotting it at the era freeze, so a change made mid-era applies to that
+ * era's payout. A compound (AutoDeposit) bucket still takes priority over it.
+ */
+@Data
+public class SetVoterRewardDestinationRequest extends ActionRequest {
+    /** Recipient in io1... form; converted to raw bytes on the wire. */
+    private String recipient;
+}

src/main/java/com/github/iotexproject/antenna/protocol/SetVoterRewardOptInRequest.java

@@ -0,0 +1,18 @@
+package com.github.iotexproject.antenna.protocol;
+
+import lombok.Data;
+
+/**
+ * setVoterRewardOptIn request.
+ *
+ * <p>Carries no fields of its own: the sender is the delegate opting in. It is
+ * one-way -- the protocol has no counterpart action to opt back out.
+ *
+ * <p>Opting in with no reward portions published on the DelegateProfile
+ * contract is silently harmful rather than rejected. The protocol cannot tell
+ * "unset" from "explicit zero", falls back to a 100% commission, and pays every
+ * voter zero while producing successful distributions. Publish portions first.
+ */
+@Data
+public class SetVoterRewardOptInRequest extends ActionRequest {
+}