[compass_app/server] Misc consistency improvements (#2539)

compass_app/server/lib/routes/booking.dart

@@ -22,7 +22,7 @@ import '../model/booking/booking.dart';
 class BookingApi {
   BookingApi() {
     // Create a default booking
-    var destination = Assets.destinations.first;
+    final destination = Assets.destinations.first;
     final activitiesRef = Assets.activities
         .where((activity) => activity.destinationRef == destination.ref)
         .map((activity) => activity.ref)

compass_app/server/lib/routes/login.dart

@@ -4,10 +4,10 @@
 
 import 'dart:convert';
 
-import 'package:compass_server/config/constants.dart';
 import 'package:shelf/shelf.dart';
 import 'package:shelf_router/shelf_router.dart';
 
+import '../config/constants.dart';
 import '../model/login_request/login_request.dart';
 import '../model/login_response/login_response.dart';
 

compass_app/server/lib/routes/user.dart

@@ -4,10 +4,11 @@
 
 import 'dart:convert';
 
-import 'package:compass_server/config/constants.dart';
 import 'package:shelf/shelf.dart';
 import 'package:shelf_router/shelf_router.dart';
 
+import '../config/constants.dart';
+
 /// Implements a simple user API.
 ///
 /// This API only returns a hardcoded user for demonstration purposes.

compass_app/server/pubspec.yaml

@@ -16,7 +16,7 @@ dependencies:
 
 dev_dependencies:
   http: ^1.1.0
-  lints: ^3.0.0
+  lints: ^5.0.0
   test: ^1.24.0
   build_runner: ^2.4.11
   freezed: ^2.5.7

compass_app/server/test/server_test.dart

@@ -21,7 +21,7 @@ void main() {
   final host = 'http://127.0.0.1:$port';
   late Process p;
 
-  var headers = {
+  final headers = {
     'Authorization': 'Bearer ${Constants.token}',
   };
 
@@ -116,7 +116,7 @@ void main() {
       headers: headers,
       body: jsonEncode(
         Booking(
-          name: "DESTINATION, CONTINENT",
+          name: 'DESTINATION, CONTINENT',
           startDate: DateTime(2024, 1, 1),
           endDate: DateTime(2024, 2, 2),
           destinationRef: 'REF',
@@ -139,7 +139,7 @@ void main() {
       headers: headers,
       body: jsonEncode(
         Booking(
-          name: "DESTINATION, CONTINENT",
+          name: 'DESTINATION, CONTINENT',
           startDate: DateTime(2024, 1, 1),
           endDate: DateTime(2024, 2, 2),
           destinationRef: 'REF',