Remove flutter chat (#26)

Had to squash merge manually as Forgejo was erroring

lib/models/configs/power_level_config.dart

@@ -1,17 +1,28 @@
 import "package:freezed_annotation/freezed_annotation.dart";
+import "package:nexus/models/content/content.dart";
 import "package:nexus/models/requests/membership_action.dart";
 part "power_level_config.freezed.dart";
-part "power_level_config.g.dart";
 
 @freezed
-abstract class PowerLevelConfig with _$PowerLevelConfig {
+sealed class PowerLevelConfig with _$PowerLevelConfig {
   const factory PowerLevelConfig({
-    @Default(false) bool isStateEvent,
-    required String eventType,
-    MembershipAction? action,
-    String? targetUser,
-  }) = _PowerLevelConfig;
+    required EventType eventType,
+    required String roomId,
+  }) = EventPowerLevelConfig;
 
-  factory PowerLevelConfig.fromJson(Map<String, Object?> json) =>
-      _$PowerLevelConfigFromJson(json);
+  const factory PowerLevelConfig.membershipAction({
+    required MembershipAction action,
+    required String targetUser,
+    required String roomId,
+  }) = MembershipActionPowerLevelConfig;
+
+  const factory PowerLevelConfig.state({
+    required EventType eventType,
+    required String roomId,
+  }) = StatePowerLevelConfig;
+
+  const factory PowerLevelConfig.redaction({
+    required String targetUser,
+    required String roomId,
+  }) = RedactionPowerLevelConfig;
 }