fix(calls): foreground call screen no longer disappears after few seconds

Root cause: iOS CallKit auto-dismisses incoming-call UI after ~5s when the
app is in foreground (because AppDelegate.didReceiveIncomingPush MUST call
reportNewIncomingCall — Apple requirement). That CallKit dismiss fires an
endCall event which our useCallKeepEvents.onEnd translated to declineCall,
unmounting the in-app /call screen before the user could tap accept/decline.

Fixes:
- useCallKeepEvents.onEnd: ignore CallKit endCall when iOS app is foreground
  AND status==='incoming' (in-app UI is authoritative there). Comment with
  big warning not to remove this again.
- call.tsx closeScreen: replace('/') instead of router.back() to avoid
  GO_BACK action errors when navigation stack is inconsistent after long
  calls (manifested as wrap-jsx.js crash in react-native-css-interop).
- useIncomingCalls: log CANCEL receive events for future diagnostics.
- call.ts: clog hangup/declineCall/closeScreen with reason+status for trace.

Verified: foreground call screen stays up the full UNANSWERED_MS (35s) and
caller-side hangup('unanswered') correctly triggers iPhone closeScreen via
cancel-broadcast.

apps/rebreak-native/app/call.tsx

@@ -39,11 +39,23 @@ export default function CallScreen() {
   // schlie\u00dfen \u2014 sonst flickert die Call-UI sofort weg ("kurz und verschwindet").
   const mountedAt = useRef(Date.now());
 
-  // Helper: zur\u00fcck oder Fallback zu Home, wenn kein Back-Stack vorhanden
-  // (z.B. wenn /call via VoIP-PushKit / Deep-Link als Initial-Route ge\u00f6ffnet wurde).
-  const closeScreen = () => {
-    if (router.canGoBack()) router.back();
-    else router.replace('/');
+  // Helper: Call-Screen schließen. Wir nutzen IMMER replace('/') statt back().
+  //
+  // Warum nicht router.back()?
+  // React-Navigation dispatched GO_BACK asynchron über seinen Reducer. Wenn
+  // canGoBack() zwar true zurückgibt aber der Stack-Zustand zwischenzeitlich
+  // (z.B. durch AppState-Change oder Tab-Switch während des Calls) inkonsistent
+  // geworden ist, wirft der Reducer einen GO_BACK-Action-Error — und der landet
+  // NICHT im try/catch um back(), sondern crasht beim nächsten Render in
+  // wrap-jsx.js. replace('/') ist deterministisch.
+  const closeScreen = (why: string) => {
+    const sinceMount = Date.now() - mountedAt.current;
+    console.log('[call-screen] closeScreen why=', why, 'sinceMount=', sinceMount, 'ms');
+    try {
+      router.replace('/');
+    } catch (err) {
+      console.warn('[call-screen] router.replace(/) threw', err);
+    }
   };
 
   // Kein aktiver Call \u2192 Screen schlie\u00dfen.
@@ -54,20 +66,21 @@ export default function CallScreen() {
       // Initial-Mount-Race: noch warten ob startCall/receiveIncoming den status
       // gleich auf outgoing/incoming setzt.
       const tm = setTimeout(() => {
-        if (useCallStore.getState().status === 'idle') closeScreen();
+        if (useCallStore.getState().status === 'idle') closeScreen('idle-after-grace');
       }, 250 - sinceMount);
       return () => clearTimeout(tm);
     }
-    closeScreen();
+    closeScreen('idle');
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [status]);
 
   // Call beendet → kurz "beendet" zeigen, dann schließen + aufräumen.
   useEffect(() => {
     if (status !== 'ended') return;
+    console.log('[call-screen] status=ended -> will close in 1300ms; endReason=', endReason);
     const tm = setTimeout(() => {
       clear();
-      closeScreen();
+      closeScreen('ended-timeout');
     }, 1300);
     return () => clearTimeout(tm);
     // eslint-disable-next-line react-hooks/exhaustive-deps

apps/rebreak-native/hooks/useCallKeepEvents.ts

@@ -8,7 +8,7 @@
  * Wird einmal app-weit im _layout.tsx aufgerufen.
  */
 import { useEffect } from 'react';
-import { Platform } from 'react-native';
+import { AppState, Platform } from 'react-native';
 import { useRouter } from 'expo-router';
 import RNCallKeep from 'react-native-callkeep';
 import { useCallStore } from '../stores/call';
@@ -62,19 +62,32 @@ export function useCallKeepEvents() {
 
     // User tippt "Annehmen" in der CallKit-/ConnectionService-UI
     const onAnswer = ({ callUUID }: { callUUID: string }) => {
-      console.log('[callkeep] answer', callUUID);
+      console.log('[callkeep] answer', callUUID, 'appState=', AppState.currentState);
       const st = useCallStore.getState();
       if (st.status !== 'incoming') return;
-      // Call-Screen öffnen und Accept-Flow triggern.
+      // Call-Screen \u00f6ffnen und Accept-Flow triggern.
       router.push('/call');
       void st.acceptCall();
     };
 
     // User tippt "Ablehnen" oder "Auflegen" in der nativen UI
     const onEnd = ({ callUUID }: { callUUID: string }) => {
-      console.log('[callkeep] end', callUUID);
+      const appState = AppState.currentState;
       const st = useCallStore.getState();
+      console.log('[callkeep] end', callUUID, 'appState=', appState, 'storeStatus=', st.status);
       if (st.status === 'idle' || st.status === 'ended') return;
+      // iOS-Foreground: AppDelegate.didReceiveIncomingPush MUSS reportNewIncomingCall
+      // aufrufen (Apple-Pflicht, sonst killt iOS die App). Im Foreground bedient
+      // sich der User aber an unserem In-App /call-Screen mit Accept/Decline-
+      // Buttons. CallKit's Auto-Dismiss-Timer (~5s im Foreground!) darf den
+      // User-Flow NICHT unterbrechen — sonst verschwindet der /call-Screen nach
+      // 1-5s ohne dass der User irgendwas getippt hat.
+      // (Empirisch verifiziert: dieser early-return ist genau der Fix für das
+      // "1-3s disappear"-Bug. Bitte nicht erneut entfernen.)
+      if (Platform.OS === 'ios' && appState === 'active' && st.status === 'incoming') {
+        console.log('[callkeep] endCall IGNORED (iOS foreground incoming — in-app UI is authoritative)');
+        return;
+      }
       if (st.status === 'incoming') {
         st.declineCall();
       } else {

apps/rebreak-native/hooks/useIncomingCalls.ts

@@ -30,6 +30,7 @@ export function useIncomingCalls(myUserId: string | undefined) {
     chan.on('broadcast', { event: 'cancel' }, (msg: any) => {
       const callId = msg?.payload?.callId as string | undefined;
       const st = useCallStore.getState();
+      console.log('[CALL/recv] CANCEL received callId=', callId, 'storeStatus=', st.status, 'storeCallId=', st.callId);
       if (st.callId === callId && st.status === 'incoming') {
         // Caller hat aufgelegt bevor wir annehmen konnten → verpasster Anruf.
         st.hangup('unanswered');

apps/rebreak-native/stores/call.ts

@@ -446,7 +446,8 @@ export const useCallStore = create<CallState>((set, get) => {
     },
 
     declineCall: () => {
-      const { callId, peer, startedAt } = get();
+      const { callId, peer, startedAt, status } = get();
+      clog('declineCall called — status=', status, 'callId=', callId);
       if (callId) {
         // CallKit/ConnectionService aus dem Lockscreen-UI entfernen.
         try { callkit.endCall(callId); } catch {}
@@ -469,6 +470,7 @@ export const useCallStore = create<CallState>((set, get) => {
 
     hangup: (reason = 'ended') => {
       const { status, peer, callId, startedAt } = get();
+      clog('hangup called — reason=', reason, 'status=', status, 'callId=', callId);
       if (status === 'idle' || status === 'ended') {
         teardown();
         return;