feat(m12): meetings + schedule conflict detection, tests, e2e

- MeetingRepository (CRUD, soft-delete, members, findMeetingsByUserInRange
  overlap) + CalendarRepository.findByCreatorInRange + TodoRepository.
  findHighPriorityByAssignee
- MeetingService (createMeeting tx+members, meeting_invited notify,
  meeting_created activity, SSE meeting.created; updateMeeting/updateMinutes/
  deleteMeeting; checkScheduleConflicts = other meetings overlap + calendar
  events overlap + high-priority todos due +-3d, time-overlap logic,
  excludeMeetingId; conflicts are warnings)
- APIs: meetings list/create/edit + /check conflict check
- Screens: meetings page + MeetingForm(member checkboxes, conflict display)
  + ConflictWarning, ProjectNav link
- Unit tests (MeetingRepository, MeetingService incl. conflict algorithm)
  + e2e meetings

app/api/projects/[projectId]/meetings/[id]/route.ts

@@ -0,0 +1,74 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { getCurrentUser } from '@/lib/auth/getCurrentUser';
+import { createMeetingService } from '@/lib/api/services';
+import { UnauthorizedError } from '@/lib/errors';
+import { handleApiError, jsonError } from '@/lib/api/handleError';
+
+export const runtime = 'nodejs';
+
+export async function PATCH(
+  request: NextRequest,
+  { params }: { params: Promise<{ projectId: string; id: string }> }
+) {
+  const user = await getCurrentUser();
+  if (!user) return handleApiError(new UnauthorizedError());
+  const { id } = 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 = createMeetingService();
+  try {
+    if (body.minutesMd !== undefined) {
+      const meeting = service.updateMinutes(
+        user.id,
+        Number(id),
+        String(body.minutesMd ?? '')
+      );
+      return NextResponse.json({ meeting });
+    }
+    const meeting = service.updateMeeting(user.id, Number(id), {
+      title: typeof body.title === 'string' ? body.title : undefined,
+      startAt: typeof body.startAt === 'string' ? body.startAt : undefined,
+      endAt: typeof body.endAt === 'string' ? body.endAt : undefined,
+      agendaMd: typeof body.agendaMd === 'string' ? body.agendaMd : undefined,
+      description:
+        typeof body.description === 'string' ? body.description : undefined,
+    });
+    return NextResponse.json({ meeting });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}
+
+export async function POST(
+  request: NextRequest,
+  { params }: { params: Promise<{ projectId: string; id: string }> }
+) {
+  // /api/projects/:projectId/meetings/check は専用ルートで処理するが、
+  // ここでは meetingId='check' の場合は重複チェックのみを行う
+  const user = await getCurrentUser();
+  if (!user) return handleApiError(new UnauthorizedError());
+  const { projectId, id } = 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 = createMeetingService();
+  try {
+    const conflicts = service.checkScheduleConflicts(
+      Number(projectId),
+      Array.isArray(body.memberIds) ? body.memberIds.map(Number) : [],
+      String(body.startAt ?? ''),
+      String(body.endAt ?? ''),
+      id === 'check' ? undefined : Number(id)
+    );
+    return NextResponse.json({ conflicts });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}

app/api/projects/[projectId]/meetings/route.ts

@@ -0,0 +1,58 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { getCurrentUser } from '@/lib/auth/getCurrentUser';
+import { createMeetingService } 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 = createMeetingService();
+  try {
+    return NextResponse.json({
+      meetings: service.getMeetings(user.id, Number(projectId)),
+    });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}
+
+export async function POST(
+  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 = createMeetingService();
+  try {
+    const result = service.createMeeting(user.id, Number(projectId), {
+      title: String(body.title ?? ''),
+      startAt: String(body.startAt ?? ''),
+      endAt: String(body.endAt ?? ''),
+      description:
+        typeof body.description === 'string' ? body.description : null,
+      location: typeof body.location === 'string' ? body.location : null,
+      meetingUrl: typeof body.meetingUrl === 'string' ? body.meetingUrl : null,
+      agendaMd: typeof body.agendaMd === 'string' ? body.agendaMd : null,
+      memberIds: Array.isArray(body.memberIds)
+        ? body.memberIds.map(Number)
+        : [],
+    });
+    return NextResponse.json(result, { status: 201 });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}

app/projects/[projectId]/meetings/page.tsx

@@ -0,0 +1,72 @@
+import { redirect } from 'next/navigation';
+import { getCurrentUser, toPublicUser } from '@/lib/auth/getCurrentUser';
+import { createMeetingService, createProjectService } from '@/lib/api/services';
+import { Header } from '@/components/layout/Header';
+import { ProjectNav } from '@/components/layout/ProjectNav';
+import { MeetingForm } from '@/components/meetings/MeetingForm';
+import { ForbiddenError, NotFoundError } from '@/lib/errors';
+
+export const dynamic = 'force-dynamic';
+
+export default async function MeetingsPage({
+  params,
+}: {
+  params: Promise<{ projectId: string }>;
+}) {
+  const user = await getCurrentUser();
+  if (!user) redirect('/login');
+  const { projectId } = await params;
+
+  const projectService = createProjectService();
+  let project: Awaited<ReturnType<typeof projectService.getProject>>;
+  try {
+    project = projectService.getProject(user.id, Number(projectId));
+  } catch (error) {
+    if (error instanceof ForbiddenError || error instanceof NotFoundError) {
+      redirect('/dashboard');
+    }
+    throw error;
+  }
+
+  const meetingService = createMeetingService();
+  const meetings = meetingService.getMeetings(user.id, project.id);
+  const members = projectService.getMembers(user.id, project.id).map((m) => ({
+    userId: m.userId,
+    name: m.user.name,
+  }));
+
+  return (
+    <div className="min-h-screen bg-gray-50">
+      <Header user={toPublicUser(user)} />
+      <ProjectNav projectId={project.id} active="meetings" />
+      <main className="mx-auto max-w-3xl space-y-6 p-6">
+        <h1 className="text-2xl font-bold">ミーティング</h1>
+        <MeetingForm projectId={project.id} members={members} />
+        <section className="space-y-3">
+          {meetings.length === 0 ? (
+            <p className="text-sm text-gray-400">ミーティングはありません。</p>
+          ) : (
+            meetings.map((m) => (
+              <div
+                key={m.id}
+                className="rounded-lg border bg-white p-4 shadow-sm"
+                data-testid={`meeting-${m.id}`}
+              >
+                <h3 className="font-semibold text-gray-800">{m.title}</h3>
+                <p className="text-xs text-gray-500">
+                  {m.startAt} 〜 {m.endAt}
+                </p>
+                {m.location && (
+                  <p className="text-xs text-gray-500">場所: {m.location}</p>
+                )}
+                {m.minutesMd && (
+                  <p className="mt-2 text-sm text-gray-600">議事録あり</p>
+                )}
+              </div>
+            ))
+          )}
+        </section>
+      </main>
+    </div>
+  );
+}