Fix auth: auto-create customer, display name flow, OTP auto-verify

- Backend: getOrCreateCustomer with phone fallback for re-login
- Backend: PATCH /api/client/auth/profile for display name update
- Client app: AuthNeedsDisplayNameData state + SetDisplayNameScreen
- Client app: ApiClient.patch method
- Both apps: handle verificationCompleted for auto-verify (test numbers)
- Both apps: skip credential sign-in if already auto-verified
- Remove debug prints from mitra auth + OTP screens
- Fix ChatRequestNotifier.startListening skips when accepting

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

client_app/lib/core/auth/auth_notifier.dart

@@ -40,6 +40,11 @@ class AuthForceRegisterData extends AuthData {
   const AuthForceRegisterData({required this.customerId, required this.displayName});
 }
 
+class AuthNeedsDisplayNameData extends AuthData {
+  final Map<String, dynamic> profile;
+  const AuthNeedsDisplayNameData(this.profile);
+}
+
 @Riverpod(keepAlive: true)
 class Auth extends _$Auth {
   FirebaseAuth get _auth => FirebaseAuth.instance;
@@ -132,7 +137,11 @@ class Auth extends _$Auth {
     final completer = Completer<void>();
     await _auth.verifyPhoneNumber(
       phoneNumber: phone,
-      verificationCompleted: (_) {
+      verificationCompleted: (credential) async {
+        try {
+          await _auth.signInWithCredential(credential);
+          state = AsyncData(await _verifyAndReturn());
+        } catch (_) {}
         if (!completer.isCompleted) completer.complete();
       },
       verificationFailed: (e) {
@@ -153,11 +162,14 @@ class Auth extends _$Auth {
   Future<void> verifyOtp(String verificationId, String smsCode) async {
     state = const AsyncLoading();
     try {
-      final credential = PhoneAuthProvider.credential(
-        verificationId: verificationId,
-        smsCode: smsCode,
-      );
-      await _auth.signInWithCredential(credential);
+      // If already signed in via auto-verification, skip credential sign-in
+      if (_auth.currentUser == null || _auth.currentUser!.isAnonymous) {
+        final credential = PhoneAuthProvider.credential(
+          verificationId: verificationId,
+          smsCode: smsCode,
+        );
+        await _auth.signInWithCredential(credential);
+      }
       state = AsyncData(await _verifyAndReturn());
     } catch (e) {
       state = AsyncError('Invalid OTP. Please try again.', StackTrace.current);
@@ -191,8 +203,24 @@ class Auth extends _$Auth {
     state = const AsyncData(AuthInitialData());
   }
 
+  Future<void> setDisplayName(String displayName) async {
+    state = const AsyncLoading();
+    try {
+      final response = await _apiClient.patch('/api/client/auth/profile', data: {
+        'display_name': displayName,
+      });
+      state = AsyncData(AuthAuthenticatedData(response['data'] as Map<String, dynamic>));
+    } catch (e) {
+      state = AsyncError('Gagal menyimpan nama. Coba lagi.', StackTrace.current);
+    }
+  }
+
   Future<AuthData> _verifyAndReturn() async {
     final response = await _apiClient.post('/api/client/auth/verify');
-    return AuthAuthenticatedData(response['data'] as Map<String, dynamic>);
+    final profile = response['data'] as Map<String, dynamic>;
+    if (profile['display_name'] == null || (profile['display_name'] as String).isEmpty) {
+      return AuthNeedsDisplayNameData(profile);
+    }
+    return AuthAuthenticatedData(profile);
   }
 }