feat: wire incoming call navigation and accept button

- Add ObserveIncomingCalls composable in AppNavigation that watches
  callManager.state and navigates to ActiveCall screen when an
  IncomingCall is detected
- Wire the accept button in CallScreen to call
  callController.acceptIncomingCall(sdpOffer), which sets the remote
  SDP, creates a WebRTC answer, and sends it back gift-wrapped
- Pass CallController to CallScreen for accept functionality

https://claude.ai/code/session_017hZm7yu7CzmcQgZGSaqSXS

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/call/CallScreen.kt

@@ -55,6 +55,7 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.vitorpamplona.amethyst.commons.call.CallManager
 import com.vitorpamplona.amethyst.commons.call.CallState
+import com.vitorpamplona.amethyst.service.call.CallController
 import com.vitorpamplona.amethyst.ui.note.ClickableUserPicture
 import com.vitorpamplona.amethyst.ui.note.UsernameDisplay
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
@@ -66,6 +67,7 @@ import kotlinx.coroutines.launch
 @Composable
 fun CallScreen(
     callManager: CallManager,
+    callController: CallController?,
     accountViewModel: AccountViewModel,
     onCallEnded: () -> Unit,
 ) {
@@ -91,7 +93,7 @@ fun CallScreen(
                 callerPubKey = state.callerPubKey,
                 callType = state.callType,
                 accountViewModel = accountViewModel,
-                onAccept = { /* handled by caller */ },
+                onAccept = { callController?.acceptIncomingCall(state.sdpOffer) },
                 onReject = { scope.launch { callManager.rejectCall() } },
             )
         }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/AppNavigation.kt

@@ -28,6 +28,7 @@ import androidx.compose.animation.fadeOut
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -39,6 +40,7 @@ import androidx.core.util.Consumer
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
 import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.call.CallState
 import com.vitorpamplona.amethyst.service.crashreports.DisplayCrashMessages
 import com.vitorpamplona.amethyst.service.relayClient.notifyCommand.compose.DisplayNotifyMessages
 import com.vitorpamplona.amethyst.ui.actions.NewUserMetadataScreen
@@ -48,6 +50,7 @@ import com.vitorpamplona.amethyst.ui.call.CallScreen
 import com.vitorpamplona.amethyst.ui.components.getActivity
 import com.vitorpamplona.amethyst.ui.components.toasts.DisplayErrorMessages
 import com.vitorpamplona.amethyst.ui.navigation.composableFromEnd
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.navigation.navs.Nav
 import com.vitorpamplona.amethyst.ui.navigation.navs.rememberNav
 import com.vitorpamplona.amethyst.ui.navigation.routes.Route
@@ -162,6 +165,23 @@ fun AppNavigation(
     DisplayNotifyMessages(accountViewModel, nav)
     DisplayCrashMessages(accountViewModel, nav)
     DisplayBroadcastProgress(accountViewModel)
+
+    ObserveIncomingCalls(accountViewModel, nav)
+}
+
+@Composable
+private fun ObserveIncomingCalls(
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val callState by accountViewModel.callManager.state.collectAsState()
+
+    LaunchedEffect(callState) {
+        val state = callState
+        if (state is CallState.IncomingCall) {
+            nav.nav(Route.ActiveCall(state.callId, state.callerPubKey))
+        }
+    }
 }
 
 @Composable
@@ -263,6 +283,7 @@ fun BuildNavigation(
         composableFromEndArgs<Route.ActiveCall> {
             CallScreen(
                 callManager = accountViewModel.callManager,
+                callController = accountViewModel.callController,
                 accountViewModel = accountViewModel,
                 onCallEnded = { nav.popBack() },
             )