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]/route.ts

@@ -0,0 +1,79 @@
+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, jsonError } from '@/lib/api/handleError';
+
+export const runtime = 'nodejs';
+
+export async function GET(
+  _request: NextRequest,
+  { params }: { params: Promise<{ projectId: string }> }
+) {
+  const user = await getCurrentUser();
+  if (!user) {
+    return handleApiError(new UnauthorizedError());
+  }
+  const { projectId } = await params;
+
+  const service = createProjectService();
+  try {
+    const dashboard = service.getDashboard(user.id, Number(projectId));
+    return NextResponse.json(dashboard);
+  } catch (error) {
+    return handleApiError(error);
+  }
+}
+
+export async function PATCH(
+  request: NextRequest,
+  { params }: { params: Promise<{ projectId: string }> }
+) {
+  const user = await getCurrentUser();
+  if (!user) {
+    return handleApiError(new UnauthorizedError());
+  }
+  const { projectId } = await params;
+
+  let body: Record<string, unknown>;
+  try {
+    body = (await request.json()) as Record<string, unknown>;
+  } catch {
+    return jsonError(400, 'リクエスト本文が不正です');
+  }
+
+  const service = createProjectService();
+  try {
+    const project = service.updateProject(user.id, Number(projectId), {
+      name: typeof body.name === 'string' ? body.name : undefined,
+      description:
+        typeof body.description === 'string' ? body.description : undefined,
+      status:
+        typeof body.status === 'string'
+          ? (body.status as 'active' | 'on_hold' | 'completed' | 'archived')
+          : undefined,
+    });
+    return NextResponse.json({ project });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}
+
+export async function DELETE(
+  _request: NextRequest,
+  { params }: { params: Promise<{ projectId: string }> }
+) {
+  const user = await getCurrentUser();
+  if (!user) {
+    return handleApiError(new UnauthorizedError());
+  }
+  const { projectId } = await params;
+
+  const service = createProjectService();
+  try {
+    service.deleteProject(user.id, Number(projectId));
+    return NextResponse.json({ ok: true });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}