refactor: Move AutoFixService, RequestApplyService, PromptBuilder, and UrlEnvService to core services

- Deleted old implementations of AutoFixService, RequestApplyService, PromptBuilder, and UrlEnvService from the chat feature.
- Introduced new implementations of AutoFixService, RequestApplyService, PromptBuilder, and UrlEnvService in the core services directory.
- Updated import paths to reflect the new structure.
- Ensured all functionalities remain intact after the refactor.

lib/dashbot/core/services/base/url_env_service.dart

@@ -0,0 +1,68 @@
+import 'package:apidash/consts.dart';
+import 'package:apidash_core/apidash_core.dart';
+
+class UrlEnvService {
+  String inferBaseUrl(String url) {
+    try {
+      final u = Uri.parse(url);
+      if (u.hasScheme && u.host.isNotEmpty) {
+        final portPart = (u.hasPort && u.port != 0) ? ':${u.port}' : '';
+        return '${u.scheme}://${u.host}$portPart';
+      }
+    } catch (_) {}
+    final m = RegExp(r'^(https?:\/\/[^\/]+)').firstMatch(url);
+    return m?.group(1) ?? '';
+  }
+
+  Future<String> ensureBaseUrlEnv(
+    String baseUrl, {
+    required Map<String, EnvironmentModel>? Function() readEnvs,
+    required String? Function() readActiveEnvId,
+    required void Function(String id, {List<EnvironmentVariableModel>? values})
+        updateEnv,
+  }) async {
+    if (baseUrl.isEmpty) return 'BASE_URL';
+    String host = 'API';
+    try {
+      final u = Uri.parse(baseUrl);
+      if (u.hasAuthority && u.host.isNotEmpty) host = u.host;
+    } catch (_) {}
+    final slug = host
+        .replaceAll(RegExp(r'[^A-Za-z0-9]+'), '_')
+        .replaceAll(RegExp(r'_+'), '_')
+        .replaceAll(RegExp(r'^_|_$'), '')
+        .toUpperCase();
+    final key = 'BASE_URL_$slug';
+
+    final envs = readEnvs();
+    String? activeId = readActiveEnvId();
+    activeId ??= kGlobalEnvironmentId;
+    final envModel = envs?[activeId];
+
+    if (envModel != null) {
+      final exists = envModel.values.any((v) => v.key == key);
+      if (!exists) {
+        final values = [...envModel.values];
+        values.add(EnvironmentVariableModel(
+          key: key,
+          value: baseUrl,
+          enabled: true,
+        ));
+        updateEnv(activeId, values: values);
+      }
+    }
+    return key;
+  }
+
+  Future<String> maybeSubstituteBaseUrl(
+    String url,
+    String baseUrl, {
+    required Future<String> Function(String baseUrl) ensure,
+  }) async {
+    if (baseUrl.isEmpty || !url.startsWith(baseUrl)) return url;
+    final key = await ensure(baseUrl);
+    final path = url.substring(baseUrl.length);
+    final normalized = path.startsWith('/') ? path : '/$path';
+    return '{{$key}}$normalized';
+  }
+}