Add voice call API types, protobuf definitions, and build dependencies

Define call method interfaces in Manager, create API records (CallInfo,
CallOffer, TurnServer), and hand-coded protobuf parsers for RingRTC
signaling messages (ConnectionParametersV4, RtpDataMessage).

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

lib/src/main/java/org/asamk/signal/manager/Manager.java

@@ -64,6 +64,10 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 
+import org.asamk.signal.manager.api.CallInfo;
+import org.asamk.signal.manager.api.CallOffer;
+import org.asamk.signal.manager.api.TurnServer;
+
 public interface Manager extends Closeable {
 
     static boolean isValidNumber(final String e164Number, final String countryCode) {
@@ -413,6 +417,30 @@ public interface Manager extends Closeable {
 
     InputStream retrieveSticker(final StickerPackId stickerPackId, final int stickerId) throws IOException;
 
+    // --- Voice call methods ---
+
+    CallInfo startCall(RecipientIdentifier.Single recipient) throws IOException, UnregisteredRecipientException;
+
+    CallInfo acceptCall(long callId) throws IOException;
+
+    void hangupCall(long callId) throws IOException;
+
+    void rejectCall(long callId) throws IOException;
+
+    List<CallInfo> listActiveCalls();
+
+    void sendCallOffer(RecipientIdentifier.Single recipient, CallOffer offer) throws IOException, UnregisteredRecipientException;
+
+    void sendCallAnswer(RecipientIdentifier.Single recipient, long callId, byte[] answerOpaque) throws IOException, UnregisteredRecipientException;
+
+    void sendIceUpdate(RecipientIdentifier.Single recipient, long callId, List<byte[]> iceCandidates) throws IOException, UnregisteredRecipientException;
+
+    void sendHangup(RecipientIdentifier.Single recipient, long callId, MessageEnvelope.Call.Hangup.Type type) throws IOException, UnregisteredRecipientException;
+
+    void sendBusy(RecipientIdentifier.Single recipient, long callId) throws IOException, UnregisteredRecipientException;
+
+    List<TurnServer> getTurnServerInfo() throws IOException;
+
     @Override
     void close();
 

lib/src/main/java/org/asamk/signal/manager/api/CallInfo.java

@@ -0,0 +1,21 @@
+package org.asamk.signal.manager.api;
+
+public record CallInfo(
+        long callId,
+        State state,
+        RecipientAddress recipient,
+        String inputDeviceName,
+        String outputDeviceName,
+        boolean isOutgoing
+) {
+
+    public enum State {
+        IDLE,
+        RINGING_INCOMING,
+        RINGING_OUTGOING,
+        CONNECTING,
+        CONNECTED,
+        RECONNECTING,
+        ENDED
+    }
+}

lib/src/main/java/org/asamk/signal/manager/api/CallOffer.java

@@ -0,0 +1,13 @@
+package org.asamk.signal.manager.api;
+
+public record CallOffer(
+        long callId,
+        Type type,
+        byte[] opaque
+) {
+
+    public enum Type {
+        AUDIO,
+        VIDEO
+    }
+}

lib/src/main/java/org/asamk/signal/manager/api/TurnServer.java

@@ -0,0 +1,10 @@
+package org.asamk.signal.manager.api;
+
+import java.util.List;
+
+public record TurnServer(
+        String username,
+        String password,
+        List<String> urls
+) {
+}

lib/src/main/java/org/asamk/signal/manager/internal/SignalDependencies.java

@@ -15,6 +15,7 @@ import org.whispersystems.signalservice.api.SignalServiceMessageSender;
 import org.whispersystems.signalservice.api.SignalSessionLock;
 import org.whispersystems.signalservice.api.account.AccountApi;
 import org.whispersystems.signalservice.api.attachment.AttachmentApi;
+import org.whispersystems.signalservice.api.calling.CallingApi;
 import org.whispersystems.signalservice.api.cds.CdsApi;
 import org.whispersystems.signalservice.api.certificate.CertificateApi;
 import org.whispersystems.signalservice.api.crypto.SignalServiceCipher;
@@ -76,6 +77,7 @@ public class SignalDependencies {
     private StorageServiceApi storageServiceApi;
     private CertificateApi certificateApi;
     private AttachmentApi attachmentApi;
+    private CallingApi callingApi;
     private MessageApi messageApi;
     private KeysApi keysApi;
     private GroupsV2Operations groupsV2Operations;
@@ -255,6 +257,13 @@ public class SignalDependencies {
                 () -> attachmentApi = new AttachmentApi(getAuthenticatedSignalWebSocket(), getPushServiceSocket()));
     }
 
+    public CallingApi getCallingApi() {
+        return getOrCreate(() -> callingApi,
+                () -> callingApi = new CallingApi(getAuthenticatedSignalWebSocket(),
+                        getUnauthenticatedSignalWebSocket(),
+                        getPushServiceSocket()));
+    }
+
     public MessageApi getMessageApi() {
         return getOrCreate(() -> messageApi,
                 () -> messageApi = new MessageApi(getAuthenticatedSignalWebSocket(),