submissions still not working, but oauth implemented and add camera sheet working.

lib/services/auth_service.dart

@@ -1,56 +1,54 @@
 import 'dart:convert';
+import 'dart:developer';
 
 import 'package:oauth2_client/oauth2_client.dart';
 import 'package:oauth2_client/oauth2_helper.dart';
 import 'package:http/http.dart' as http;
 
-/// Handles OAuth 2 PKCE login to OpenStreetMap and exposes
-/// the stored access token & display name.
-///
-/// ─ Requirements ─
-/// • Register an OAuth app at
-///   https://www.openstreetmap.org/oauth2/applications
-///   ‑ Redirect URI: flockmap://auth
-/// • Put that client ID below (replace 'flockmap').
+/// Handles PKCE OAuth login with OpenStreetMap.
 class AuthService {
-  static const _clientId = 'lzEr2zjBGZ2TvJWr3QGxNcKxigp-mQ6pRWIUhI_Bqx8';
+  /// Paste the **client ID** shown on the OSM OAuth2 application page
+  /// (it can be alphanumeric like ‘lzEr2zjBGZ2…’).
+  static const String _clientId = 'lzEr2zjBGZ2TvJWr3QGxNcKxigp-mQ6pRWIUhI_Bqx8';
   static const _redirect = 'flockmap://auth';
 
   late final OAuth2Helper _helper;
-
-  String? _displayName; // cached after login
-  String? get displayName => _displayName;
+  String? _displayName;
 
   AuthService() {
     final client = OAuth2Client(
       authorizeUrl: 'https://www.openstreetmap.org/oauth2/authorize',
       tokenUrl: 'https://www.openstreetmap.org/oauth2/token',
       redirectUri: _redirect,
-      customUriScheme: 'flockmap',             // matches redirect scheme
+      customUriScheme: 'flockmap',
     );
 
     _helper = OAuth2Helper(
       client,
       clientId: _clientId,
       scopes: ['write_api'],
-      enablePKCE: true,                        // PKCE flow
-      // No custom token store needed: oauth2_client will
-      // auto‑use flutter_secure_storage when present.
+      enablePKCE: true,
     );
   }
 
-  /* ───────── Public helpers ───────── */
-
-  /// Returns `true` if a non‑expired token is stored.
   Future<bool> isLoggedIn() async =>
       (await _helper.getTokenFromStorage())?.isExpired() == false;
 
-  /// Launches browser login if necessary; caches display name.
+  String? get displayName => _displayName;
+
   Future<String?> login() async {
-    final token = await _helper.getToken();
-    if (token?.accessToken == null) return null;
-    _displayName = await _fetchUsername(token!.accessToken!);
-    return _displayName;
+    try {
+      final token = await _helper.getToken();
+      if (token?.accessToken == null) {
+        log('OAuth error: token null or missing accessToken');
+        return null;
+      }
+      _displayName = await _fetchUsername(token!.accessToken!);
+      return _displayName;
+    } catch (e) {
+      log('OAuth login failed: $e');
+      rethrow;
+    }
   }
 
   Future<void> logout() async {
@@ -58,18 +56,20 @@ class AuthService {
     _displayName = null;
   }
 
-  /// Safely fetch current access token (or null).
   Future<String?> getAccessToken() async =>
       (await _helper.getTokenFromStorage())?.accessToken;
 
-  /* ───────── Internal ───────── */
+  /* ───────── helper ───────── */
 
   Future<String?> _fetchUsername(String accessToken) async {
     final resp = await http.get(
       Uri.parse('https://api.openstreetmap.org/api/0.6/user/details.json'),
       headers: {'Authorization': 'Bearer $accessToken'},
     );
-    if (resp.statusCode != 200) return null;
+    if (resp.statusCode != 200) {
+      log('fetchUsername response ${resp.statusCode}: ${resp.body}');
+      return null;
+    }
     return jsonDecode(resp.body)['user']?['display_name'];
   }
 }