feat(m4): project & member management with tests and e2e

- ProjectRepository, ProjectMemberRepository, minimal NotificationRepository
- ProjectService: create/update/archive/delete project, add/remove member,
  permission checks (isMember/admin), member-added notification, getDashboard
  skeleton, getMyProjects, getMemberRole
- projectValidator, API services factory
- API routes: projects CRUD, members list/add/remove
- Screens: dashboard (project list + create form), project overview, members,
  settings; layout (Header/Sidebar/ProjectNav) and project components
- Unit tests (Project/ProjectMember repositories, ProjectService),
  integration project-member-permission, e2e project-management

lib/validators/projectValidator.ts

@@ -0,0 +1,66 @@
+import { ValidationError } from '@/lib/errors';
+import type { ProjectStatus } from '@/lib/types';
+
+const MAX_NAME_LENGTH = 200;
+const MAX_DESCRIPTION_LENGTH = 2000;
+const VALID_STATUSES: ProjectStatus[] = [
+  'active',
+  'on_hold',
+  'completed',
+  'archived',
+];
+
+export interface ProjectCreateInput {
+  name: string;
+  description?: string;
+}
+
+export interface ProjectUpdateInput {
+  name?: string;
+  description?: string;
+  status?: ProjectStatus;
+}
+
+export function validateProjectCreate(input: ProjectCreateInput): void {
+  if (!input.name || !input.name.trim()) {
+    throw new ValidationError('プロジェクト名を入力してください', 'name');
+  }
+  if (input.name.length > MAX_NAME_LENGTH) {
+    throw new ValidationError(
+      `プロジェクト名は${MAX_NAME_LENGTH}文字以内で入力してください`,
+      'name'
+    );
+  }
+  if (input.description && input.description.length > MAX_DESCRIPTION_LENGTH) {
+    throw new ValidationError(
+      `説明文は${MAX_DESCRIPTION_LENGTH}文字以内で入力してください`,
+      'description'
+    );
+  }
+}
+
+export function validateProjectUpdate(input: ProjectUpdateInput): void {
+  if (input.name !== undefined) {
+    if (!input.name.trim()) {
+      throw new ValidationError('プロジェクト名を入力してください', 'name');
+    }
+    if (input.name.length > MAX_NAME_LENGTH) {
+      throw new ValidationError(
+        `プロジェクト名は${MAX_NAME_LENGTH}文字以内で入力してください`,
+        'name'
+      );
+    }
+  }
+  if (
+    input.description !== undefined &&
+    input.description.length > MAX_DESCRIPTION_LENGTH
+  ) {
+    throw new ValidationError(
+      `説明文は${MAX_DESCRIPTION_LENGTH}文字以内で入力してください`,
+      'description'
+    );
+  }
+  if (input.status !== undefined && !VALID_STATUSES.includes(input.status)) {
+    throw new ValidationError('無効なステータスです', 'status');
+  }
+}