treewide(refactor): rename files to follow the same style

lib/controllers/user.dart

@@ -0,0 +1,47 @@
+import "dart:async";
+import "package:collection/collection.dart";
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:nexus/controllers/members.dart";
+import "package:nexus/controllers/profile.dart";
+import "package:nexus/helpers/extensions/get_localpart.dart";
+import "package:nexus/models/configs/user.dart";
+import "package:nexus/models/content/membership.dart";
+
+class UserController extends AsyncNotifier<MembershipContent> {
+  final UserConfig config;
+  UserController(this.config);
+
+  @override
+  Future<MembershipContent> build() async {
+    final member = config.roomId == null
+        ? null
+        : await ref.watch(
+            MembersController.provider(config.roomId!).selectAsync(
+              (value) => value.firstWhereOrNull(
+                (membership) => membership.stateKey == config.userId,
+              ),
+            ),
+          );
+
+    if (member?.content case final MembershipContent content) {
+      return content;
+    }
+
+    final profile = await ref.watch(
+      ProfileController.provider(config.userId).future,
+    );
+
+    return .new(
+      status: .leave,
+      avatarUrl: profile.avatarUrl,
+      displayName: profile.displayName ?? config.userId.localpart,
+    );
+  }
+
+  static final provider =
+      AsyncNotifierProvider.family<
+        UserController,
+        MembershipContent,
+        UserConfig
+      >(UserController.new);
+}