feat(m11): calendar + milestones with progress calc, tests, e2e

- CalendarRepository (event CRUD, range query, soft-delete, project isolation)
  + MilestoneRepository (CRUD, findToDosByMilestone) + ScheduleService
  (aggregated getCalendarEvents = custom events+milestones+todos in range,
  milestone CRUD, milestone_updated activity, progress auto-calc 0-100)
- APIs: calendar events GET/POST/PATCH/DELETE, milestones GET/POST/PATCH +
  progress
- Screens: calendar list view + CalendarEventForm, milestones list with
  progress bars + MilestoneForm, ProjectNav links
- Unit tests (CalendarRepository, MilestoneRepository, ScheduleService incl.
  progress calc 0/33/100) + e2e calendar

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

@@ -0,0 +1,60 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { getCurrentUser } from '@/lib/auth/getCurrentUser';
+import { createScheduleService } 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 = createScheduleService();
+  try {
+    const milestone = service.updateMilestone(user.id, Number(id), {
+      title: typeof body.title === 'string' ? body.title : undefined,
+      dueDate:
+        typeof body.dueDate === 'string'
+          ? body.dueDate
+          : body.dueDate === null
+            ? null
+            : undefined,
+      status:
+        typeof body.status === 'string'
+          ? (body.status as 'open' | 'closed')
+          : undefined,
+      description:
+        typeof body.description === 'string' ? body.description : undefined,
+    });
+    return NextResponse.json({ milestone });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}
+
+export async function GET(
+  _request: NextRequest,
+  { params }: { params: Promise<{ projectId: string; id: string }> }
+) {
+  const user = await getCurrentUser();
+  if (!user) return handleApiError(new UnauthorizedError());
+  const { id } = await params;
+  const service = createScheduleService();
+  try {
+    return NextResponse.json({
+      progress: service.getMilestoneProgress(user.id, Number(id)),
+    });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}

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

@@ -0,0 +1,51 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { getCurrentUser } from '@/lib/auth/getCurrentUser';
+import { createScheduleService } 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 = createScheduleService();
+  try {
+    return NextResponse.json({
+      milestones: service.getMilestones(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 = createScheduleService();
+  try {
+    const milestone = service.createMilestone(user.id, Number(projectId), {
+      title: String(body.title ?? ''),
+      dueDate: typeof body.dueDate === 'string' ? body.dueDate : null,
+      description:
+        typeof body.description === 'string' ? body.description : null,
+    });
+    return NextResponse.json({ milestone }, { status: 201 });
+  } catch (error) {
+    return handleApiError(error);
+  }
+}