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

app/api/projects/[projectId]/members/[userId]/route.ts

@@ -0,0 +1,30 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { getCurrentUser } from '@/lib/auth/getCurrentUser';
+import { createProjectService } from '@/lib/api/services';
+import { UnauthorizedError } from '@/lib/errors';
+import { handleApiError } from '@/lib/api/handleError';
+
+export const runtime = 'nodejs';
+
+export async function DELETE(
+  _request: NextRequest,
+  {
+    params,
+  }: {
+    params: Promise<{ projectId: string; userId: string }>;
+  }
+) {
+  const user = await getCurrentUser();
+  if (!user) {
+    return handleApiError(new UnauthorizedError());
+  }
+  const { projectId, userId } = await params;
+
+  const service = createProjectService();
+  try {
+    service.removeMember(user.id, Number(projectId), Number(userId));
+    return NextResponse.json({ ok: true });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}