Add TTS toggle button to voice controls

Voice toolbar now shows three controls when voice is enabled:
- Mic toggle (voice on/off)
- TTS toggle (speaker icon, sends /voice tts)
- Push to Talk (waveform, sends Ctrl+B)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scarf/scarf/Features/Chat/ViewModels/ChatViewModel.swift

@@ -10,6 +10,9 @@ final class ChatViewModel {
     var sessionPreviews: [String: String] = [:]
     var terminalView: LocalProcessTerminalView?
     var hasActiveProcess = false
+    var voiceEnabled = false
+    var ttsEnabled = false
+    var isRecording = false
     private var coordinator: Coordinator?
 
     var hermesBinaryExists: Bool {
@@ -17,14 +20,23 @@ final class ChatViewModel {
     }
 
     func startNewSession() {
+        voiceEnabled = false
+        ttsEnabled = false
+        isRecording = false
         launchTerminal(arguments: ["chat"])
     }
 
     func resumeSession(_ sessionId: String) {
+        voiceEnabled = false
+        ttsEnabled = false
+        isRecording = false
         launchTerminal(arguments: ["chat", "--resume", sessionId])
     }
 
     func continueLastSession() {
+        voiceEnabled = false
+        ttsEnabled = false
+        isRecording = false
         launchTerminal(arguments: ["chat", "--continue"])
     }
 
@@ -42,6 +54,37 @@ final class ChatViewModel {
         return session.id
     }
 
+    func toggleVoice() {
+        guard let tv = terminalView else { return }
+        if voiceEnabled {
+            sendToTerminal(tv, text: "/voice off\r")
+            voiceEnabled = false
+            isRecording = false
+        } else {
+            sendToTerminal(tv, text: "/voice on\r")
+            voiceEnabled = true
+        }
+    }
+
+    func toggleTTS() {
+        guard let tv = terminalView, voiceEnabled else { return }
+        sendToTerminal(tv, text: "/voice tts\r")
+        ttsEnabled.toggle()
+    }
+
+    func pushToTalk() {
+        guard let tv = terminalView, voiceEnabled else { return }
+        // Ctrl+B = ASCII 0x02
+        let ctrlB: [UInt8] = [0x02]
+        tv.send(source: tv, data: ctrlB[0..<1])
+        isRecording.toggle()
+    }
+
+    private func sendToTerminal(_ tv: LocalProcessTerminalView, text: String) {
+        let bytes = Array(text.utf8)
+        tv.send(source: tv, data: bytes[0..<bytes.count])
+    }
+
     private func launchTerminal(arguments: [String]) {
         if let existing = terminalView {
             existing.terminate()
@@ -55,6 +98,8 @@ final class ChatViewModel {
 
         let coord = Coordinator(onTerminated: { [weak self] in
             self?.hasActiveProcess = false
+            self?.voiceEnabled = false
+            self?.isRecording = false
         })
         terminal.processDelegate = coord
         self.coordinator = coord

scarf/scarf/Features/Chat/Views/ChatView.swift

@@ -105,12 +105,26 @@ struct ChatView: View {
             .help("Toggle voice mode (/voice)")
 
             if viewModel.voiceEnabled {
+                Button {
+                    viewModel.toggleTTS()
+                } label: {
+                    HStack(spacing: 4) {
+                        Image(systemName: viewModel.ttsEnabled ? "speaker.wave.2.fill" : "speaker.slash")
+                            .foregroundStyle(viewModel.ttsEnabled ? .green : .secondary)
+                        Text(viewModel.ttsEnabled ? "TTS On" : "TTS Off")
+                            .font(.caption)
+                            .foregroundStyle(viewModel.ttsEnabled ? .primary : .secondary)
+                    }
+                }
+                .buttonStyle(.plain)
+                .help("Toggle text-to-speech (/voice tts)")
+
                 Button {
                     viewModel.pushToTalk()
                 } label: {
                     HStack(spacing: 4) {
                         Image(systemName: viewModel.isRecording ? "waveform.circle.fill" : "waveform.circle")
-                            .foregroundStyle(viewModel.isRecording ? .red : .accentColor)
+                            .foregroundStyle(viewModel.isRecording ? .red : Color.accentColor)
                             .symbolEffect(.pulse, isActive: viewModel.isRecording)
                         Text(viewModel.isRecording ? "Recording..." : "Push to Talk")
                             .font(.caption)