feat: custom headers initial support

mobile/lib/core/network/dio_provider.dart

@@ -42,10 +42,14 @@ Dio dio(Ref ref) {
 
   dio.options.connectTimeout = const Duration(seconds: 10);
   dio.options.receiveTimeout = const Duration(seconds: 10);
-  dio.options.headers = {
+  final customHeaders = ref.watch(customHeadersProvider).value ?? [];
+  final Map<String, String> headers = {
     'Content-Type': 'application/json',
     'Accept': 'application/json',
+    for (final h in customHeaders)
+      if (h.key.trim().isNotEmpty) h.key.trim(): h.value,
   };
+  dio.options.headers = headers;
 
   // Allow self-signed certificates when the user has enabled the setting
   final allowSelfSigned =
@@ -95,6 +99,8 @@ Dio dio(Ref ref) {
               refreshDio.options.headers = {
                 'Content-Type': 'application/json',
                 'Accept': 'application/json',
+                for (final h in customHeaders)
+                  if (h.key.trim().isNotEmpty) h.key.trim(): h.value,
               };
               if (allowSelfSigned && serverUrl != null && serverUrl.isNotEmpty) {
                 refreshDio.httpClientAdapter =

mobile/lib/core/network/server_config_provider.dart

@@ -1,3 +1,4 @@
+import 'dart:convert';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_secure_storage/flutter_secure_storage.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';
@@ -6,7 +7,8 @@ part 'server_config_provider.g.dart';
 
 const _serverUrlKey = 'server_url';
 const _allowSelfSignedCertKey = 'allow_self_signed_cert';
-
+const _customHeadersKey = 'custom_headers';
+const int maxCustomHeaders = 10;
 @riverpod
 class ServerConfig extends _$ServerConfig {
   final _storage = const FlutterSecureStorage();
@@ -73,3 +75,68 @@ final allowSelfSignedCertProvider =
     AsyncNotifierProvider<AllowSelfSignedCertNotifier, bool>(
       AllowSelfSignedCertNotifier.new,
     );
+class CustomHeader {
+  final String key;
+  final String value;
+  const CustomHeader({required this.key, required this.value});
+  Map<String, String> toJson() => {'key': key, 'value': value};
+  factory CustomHeader.fromJson(Map<String, dynamic> json) =>
+      CustomHeader(key: json['key'] as String, value: json['value'] as String);
+  CustomHeader copyWith({String? key, String? value}) =>
+      CustomHeader(key: key ?? this.key, value: value ?? this.value);
+}
+class CustomHeadersNotifier extends AsyncNotifier<List<CustomHeader>> {
+  final _storage = const FlutterSecureStorage();
+  @override
+  Future<List<CustomHeader>> build() async {
+    try {
+      final raw = await _storage.read(key: _customHeadersKey);
+      if (raw == null) return [];
+      final list = jsonDecode(raw) as List<dynamic>;
+      return list
+          .cast<Map<String, dynamic>>()
+          .map(CustomHeader.fromJson)
+          .toList();
+    } catch (_) {
+      return [];
+    }
+  }
+  Future<void> _persist(List<CustomHeader> headers) async {
+    try {
+      final encoded = jsonEncode(headers.map((h) => h.toJson()).toList());
+      await _storage.write(key: _customHeadersKey, value: encoded);
+    } catch (_) {
+      // Ignore storage errors
+    }
+  }
+  Future<void> addHeader(CustomHeader header) async {
+    final current = state.value ?? [];
+    if (current.length >= maxCustomHeaders) return;
+    final updated = [...current, header];
+    state = AsyncData(updated);
+    await _persist(updated);
+  }
+  Future<void> updateHeader(int index, CustomHeader header) async {
+    final current = List<CustomHeader>.from(state.value ?? []);
+    if (index < 0 || index >= current.length) return;
+    current[index] = header;
+    state = AsyncData(current);
+    await _persist(current);
+  }
+  Future<void> removeHeader(int index) async {
+    final current = List<CustomHeader>.from(state.value ?? []);
+    if (index < 0 || index >= current.length) return;
+    current.removeAt(index);
+    state = AsyncData(current);
+    await _persist(current);
+  }
+  Future<void> setHeaders(List<CustomHeader> headers) async {
+    final limited = headers.take(maxCustomHeaders).toList();
+    state = AsyncData(limited);
+    await _persist(limited);
+  }
+}
+final customHeadersProvider =
+    AsyncNotifierProvider<CustomHeadersNotifier, List<CustomHeader>>(
+      CustomHeadersNotifier.new,
+    );