Add Live Call UI overlay + wiring in ChatScreen

LiveCallOverlay — fullscreen composable: KaizenOrb (amplitude-reactive,
streaming/recording variants), duration timer, status text (connecting/
listening/speaking), animated subtitle (transcript/response), end call
button (red gradient circle with PhoneOff icon), interrupt on orb tap.

ChatScreen wiring: CallButton → startLiveCall() → binds LiveCallService
→ Foreground Service with AudioPipeline + LiveClient. Overlay renders
above chat content with fade animation. endLiveCall() unbinds + stops.

ChatInput: onCallClick callback propagated from CallButton to ChatScreen.

i18n: live_connecting/listening/ready/speaking/end/reconnecting in de+en.
KaizenIcons: added PhoneOff (Lucide).

app/src/main/java/dev/kaizen/app/chat/ChatComponents.kt

@@ -791,6 +791,7 @@ fun ChatInput(
     isRecording: Boolean = false,
     recordingAmplitude: Float = 0f,
     onMicClick: () -> Unit = {},
+    onCallClick: () -> Unit = {},
     pendingFiles: List<PendingFile> = emptyList(),
     onAddClick: () -> Unit = {},
     onRemoveFile: (String) -> Unit = {},
@@ -922,7 +923,7 @@ fun ChatInput(
                     } else if (hasContent) {
                         SendButton(enabled = canSend, onClick = onSend)
                     } else {
-                        CallButton(onClick = { /* TODO: call feature */ })
+                        CallButton(onClick = onCallClick)
                     }
                 }
             }

app/src/main/java/dev/kaizen/app/chat/ChatScreen.kt

@@ -92,11 +92,17 @@ import androidx.core.content.ContextCompat
 import androidx.compose.animation.core.Spring
 import androidx.compose.animation.core.spring
 import androidx.compose.animation.core.tween
+import android.content.ComponentName
+import android.content.ServiceConnection
+import android.os.IBinder
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.async
 import kotlinx.coroutines.launch
 import java.io.ByteArrayOutputStream
 import java.io.File
+import dev.kaizen.app.live.CallStatus
+import dev.kaizen.app.live.LiveCallOverlay
+import dev.kaizen.app.live.LiveCallService
 
 // Screen enumeration for modular state-driven navigation (Zero Technical Debt)
 enum class AppScreen { Chat, Settings }
@@ -154,6 +160,16 @@ fun ChatScreen(
     val audioFileRef = remember { mutableStateOf<File?>(null) }
     var recordingAmplitude by remember { mutableStateOf(0f) }
 
+    // ─── Live Call state (uses context/ttsVoice/currentConversationId declared below) ───
+    var liveService by remember { mutableStateOf<LiveCallService?>(null) }
+    var liveCallActive by remember { mutableStateOf(false) }
+    val liveStatus by liveService?.status?.collectAsState() ?: remember { mutableStateOf(CallStatus.IDLE) }
+    val liveSubtitle by liveService?.subtitle?.collectAsState() ?: remember { mutableStateOf("") }
+    val liveAmplitude by liveService?.amplitude?.collectAsState() ?: remember { mutableStateOf(0f) }
+    val liveUserSpeaking by liveService?.userSpeaking?.collectAsState() ?: remember { mutableStateOf(false) }
+    var liveStartedAt by remember { mutableStateOf(0L) }
+    var liveElapsedMs by remember { mutableStateOf(0L) }
+
     LaunchedEffect(isRecording) {
         if (!isRecording) { recordingAmplitude = 0f; return@LaunchedEffect }
         while (isRecording) {
@@ -201,6 +217,59 @@ fun ChatScreen(
     val pendingFiles = remember { mutableStateListOf<PendingFile>() }
     val context = LocalContext.current
 
+    // ─── Live Call service binding + control ──────────────────────────────
+    val liveServiceConnection = remember {
+        object : ServiceConnection {
+            override fun onServiceConnected(name: ComponentName?, binder: IBinder?) {
+                liveService = (binder as? LiveCallService.LocalBinder)?.service
+            }
+            override fun onServiceDisconnected(name: ComponentName?) {
+                liveService = null
+            }
+        }
+    }
+
+    LaunchedEffect(liveCallActive) {
+        if (liveCallActive) {
+            liveStartedAt = System.currentTimeMillis()
+            while (liveCallActive) {
+                liveElapsedMs = System.currentTimeMillis() - liveStartedAt
+                kotlinx.coroutines.delay(500)
+            }
+        }
+    }
+
+    fun startLiveCall() {
+        val cfg = session.config ?: return
+        liveCallActive = true
+
+        val intent = LiveCallService.intent(context)
+        context.startForegroundService(intent)
+        context.bindService(intent, liveServiceConnection, 0)
+
+        scope.launch {
+            var attempts = 0
+            while (liveService == null && attempts < 20) {
+                kotlinx.coroutines.delay(50)
+                attempts++
+            }
+            liveService?.startCall(
+                baseUrl = cfg.baseUrl,
+                token = cfg.token,
+                model = cfg.model,
+                voice = ttsVoice,
+                conversationId = conversationId,
+            )
+        }
+    }
+
+    fun endLiveCall() {
+        liveService?.endCall()
+        liveCallActive = false
+        try { context.unbindService(liveServiceConnection) } catch (_: Exception) {}
+        liveService = null
+    }
+
     var showAttachMenu by remember { mutableStateOf(false) }
 
     fun uploadPickedFile(name: String, mimeType: String, bytes: ByteArray) {
@@ -1205,6 +1274,7 @@ fun ChatScreen(
                                 isRecording = isRecording,
                                 recordingAmplitude = recordingAmplitude,
                                 onMicClick = { toggleRecording() },
+                                onCallClick = { startLiveCall() },
                                 pendingFiles = pendingFiles,
                                 onAddClick = { showAttachMenu = !showAttachMenu },
                                 onRemoveFile = { id -> pendingFiles.removeAll { it.id == id } },
@@ -1302,6 +1372,23 @@ fun ChatScreen(
                     }
                 }
             }
+
+            // ─── Live Call Overlay ────────────────────────────────
+            androidx.compose.animation.AnimatedVisibility(
+                visible = liveCallActive,
+                enter = androidx.compose.animation.fadeIn(tween(250)),
+                exit = androidx.compose.animation.fadeOut(tween(200)),
+            ) {
+                LiveCallOverlay(
+                    status = liveStatus,
+                    subtitle = liveSubtitle,
+                    amplitude = liveAmplitude,
+                    userSpeaking = liveUserSpeaking,
+                    elapsedMs = liveElapsedMs,
+                    onEndCall = { endLiveCall() },
+                    onInterrupt = { liveService?.interrupt() },
+                )
+            }
         }
     }
 }

app/src/main/java/dev/kaizen/app/live/LiveCallOverlay.kt

@@ -0,0 +1,181 @@
+package dev.kaizen.app.live
+
+import androidx.compose.animation.*
+import androidx.compose.animation.core.*
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.interaction.collectIsPressedAsState
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.foundation.layout.*
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.alpha
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.scale
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import dev.kaizen.app.R
+import dev.kaizen.app.chat.KaizenOrb
+import dev.kaizen.app.ui.effect.GlassSurface
+import dev.kaizen.app.ui.effect.KaizenShadows
+import dev.kaizen.app.ui.icon.KaizenIcons
+import dev.kaizen.app.ui.shape.KaizenShapes
+import dev.kaizen.app.ui.theme.LocalKaizenAccent
+
+@Composable
+fun LiveCallOverlay(
+    status: CallStatus,
+    subtitle: String,
+    amplitude: Float,
+    userSpeaking: Boolean,
+    elapsedMs: Long,
+    onEndCall: () -> Unit,
+    onInterrupt: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    val isDark = isSystemInDarkTheme()
+    val accent = LocalKaizenAccent.current
+    val cs = MaterialTheme.colorScheme
+
+    Box(
+        modifier
+            .fillMaxSize()
+            .background(
+                if (isDark) Color.Black.copy(alpha = 0.85f)
+                else Color.White.copy(alpha = 0.88f)
+            )
+            .statusBarsPadding()
+            .navigationBarsPadding(),
+        contentAlignment = Alignment.Center,
+    ) {
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(24.dp),
+            modifier = Modifier.fillMaxWidth().padding(horizontal = 32.dp),
+        ) {
+            // ─── Duration ─────────────────────────────────────────
+            val elapsed = elapsedMs / 1000
+            val min = elapsed / 60
+            val sec = elapsed % 60
+            Text(
+                String.format("%d:%02d", min, sec),
+                color = cs.onSurface.copy(alpha = 0.5f),
+                fontSize = 14.sp,
+                fontWeight = FontWeight.W400,
+                letterSpacing = 1.sp,
+            )
+
+            // ─── Orb ──────────────────────────────────────────────
+            val isActive = status == CallStatus.LISTENING || status == CallStatus.SPEAKING
+            Box(
+                Modifier
+                    .size(180.dp)
+                    .then(
+                        if (status == CallStatus.SPEAKING) {
+                            Modifier.clickable(
+                                interactionSource = remember { MutableInteractionSource() },
+                                indication = null,
+                                onClick = onInterrupt,
+                            )
+                        } else Modifier
+                    ),
+                contentAlignment = Alignment.Center,
+            ) {
+                KaizenOrb(
+                    size = 160.dp,
+                    streaming = status == CallStatus.SPEAKING,
+                    recording = status == CallStatus.LISTENING && userSpeaking,
+                    amplitude = if (isActive) amplitude else null,
+                )
+            }
+
+            // ─── Status text ──────────────────────────────────────
+            val statusText = when (status) {
+                CallStatus.IDLE -> ""
+                CallStatus.CONNECTING -> stringResource(R.string.live_connecting)
+                CallStatus.LISTENING -> if (userSpeaking) stringResource(R.string.live_listening)
+                                        else stringResource(R.string.live_ready)
+                CallStatus.SPEAKING -> stringResource(R.string.live_speaking)
+            }
+
+            Text(
+                statusText,
+                color = when (status) {
+                    CallStatus.SPEAKING -> accent.primary
+                    CallStatus.LISTENING -> if (userSpeaking) accent.primary.copy(alpha = 0.8f)
+                                            else cs.onSurface.copy(alpha = 0.4f)
+                    else -> cs.onSurface.copy(alpha = 0.4f)
+                },
+                fontSize = 13.sp,
+                fontWeight = FontWeight.W400,
+                letterSpacing = 0.5.sp,
+            )
+
+            // ─── Subtitle (transcript / KI response) ─────────────
+            AnimatedVisibility(
+                visible = subtitle.isNotEmpty(),
+                enter = fadeIn(tween(200)) + expandVertically(),
+                exit = fadeOut(tween(150)) + shrinkVertically(),
+            ) {
+                Text(
+                    subtitle,
+                    color = cs.onSurface.copy(alpha = 0.75f),
+                    fontSize = 15.sp,
+                    fontWeight = FontWeight.W300,
+                    textAlign = TextAlign.Center,
+                    maxLines = 4,
+                    overflow = TextOverflow.Ellipsis,
+                    lineHeight = 22.sp,
+                    modifier = Modifier.fillMaxWidth(),
+                )
+            }
+
+            Spacer(Modifier.height(32.dp))
+
+            // ─── End Call button ──────────────────────────────────
+            EndCallButton(onClick = onEndCall)
+        }
+    }
+}
+
+@Composable
+private fun EndCallButton(onClick: () -> Unit) {
+    val interaction = remember { MutableInteractionSource() }
+    val pressed by interaction.collectIsPressedAsState()
+    val pressScale by animateFloatAsState(if (pressed) 0.9f else 1f, label = "end")
+
+    Box(
+        Modifier
+            .size(64.dp)
+            .scale(pressScale)
+            .clip(KaizenShapes.circle)
+            .background(
+                Brush.verticalGradient(
+                    listOf(
+                        Color(0xFFEF4444),
+                        Color(0xFFDC2626),
+                    )
+                )
+            )
+            .clickable(interactionSource = interaction, indication = null, onClick = onClick),
+        contentAlignment = Alignment.Center,
+    ) {
+        Icon(
+            KaizenIcons.PhoneOff,
+            contentDescription = stringResource(R.string.live_end),
+            tint = Color.White,
+            modifier = Modifier.size(28.dp),
+        )
+    }
+}

app/src/main/java/dev/kaizen/app/ui/icon/KaizenIcons.kt

@@ -97,8 +97,9 @@ object KaizenIcons {
     val ArrowDown: ImageVector get()     = Lucide.ArrowDown
     val ArrowUp: ImageVector get()       = Lucide.ArrowUp
 
-    // ── Audio ──────────────────────────────────────────────────────────────
+    // ── Audio / Call ────────────────────────────────────────────────────────
     val Volume2: ImageVector get()       = Lucide.Volume2
+    val PhoneOff: ImageVector get()      = Lucide.PhoneOff
 
     // ── Custom (brand overrides) ────────────────────────────────────────────
     // Add hand-drawn SVGs here as ImageVector literals when ready.

app/src/main/res/values-en/strings.xml

@@ -180,4 +180,12 @@
     <string name="settings_language_system">System</string>
     <string name="settings_language_de">Deutsch</string>
     <string name="settings_language_en">English</string>
+
+    <!-- Live Call -->
+    <string name="live_connecting">Connecting…</string>
+    <string name="live_listening">Listening…</string>
+    <string name="live_ready">Just start talking</string>
+    <string name="live_speaking">Responding…</string>
+    <string name="live_end">End</string>
+    <string name="live_reconnecting">Reconnecting…</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -182,4 +182,12 @@
     <string name="settings_language_system">System</string>
     <string name="settings_language_de">Deutsch</string>
     <string name="settings_language_en">English</string>
+
+    <!-- Live Call -->
+    <string name="live_connecting">Verbinde…</string>
+    <string name="live_listening">Hört zu…</string>
+    <string name="live_ready">Sprich einfach los</string>
+    <string name="live_speaking">Antwortet…</string>
+    <string name="live_end">Beenden</string>
+    <string name="live_reconnecting">Verbindung wird wiederhergestellt…</string>
 </resources>