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/projects/[projectId]/calendar/page.tsx

@@ -0,0 +1,95 @@
+import { redirect } from 'next/navigation';
+import { getCurrentUser, toPublicUser } from '@/lib/auth/getCurrentUser';
+import {
+  createScheduleService,
+  createProjectService,
+} from '@/lib/api/services';
+import { Header } from '@/components/layout/Header';
+import { ProjectNav } from '@/components/layout/ProjectNav';
+import { CalendarEventForm } from '@/components/calendar/CalendarEventForm';
+import { ForbiddenError, NotFoundError } from '@/lib/errors';
+
+export const dynamic = 'force-dynamic';
+
+const SOURCE_COLORS: Record<string, string> = {
+  event: 'bg-blue-100 text-blue-700',
+  milestone: 'bg-purple-100 text-purple-700',
+  todo: 'bg-yellow-100 text-yellow-700',
+};
+
+export default async function CalendarPage({
+  params,
+  searchParams,
+}: {
+  params: Promise<{ projectId: string }>;
+  searchParams: Promise<{ from?: string; to?: string }>;
+}) {
+  const user = await getCurrentUser();
+  if (!user) redirect('/login');
+  const { projectId } = await params;
+  const { from, to } = await searchParams;
+
+  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;
+  }
+
+  // デフォルトは当月
+  const now = new Date();
+  const defaultFrom = `${now.getFullYear()}-${String(now.getMonth() + 1).padStart(2, '0')}-01`;
+  const rangeFrom = from ?? defaultFrom;
+  const rangeTo = to ?? defaultFrom.replace(/-01$/, '-28');
+
+  const scheduleService = createScheduleService();
+  const events = scheduleService.getCalendarEvents(user.id, project.id, {
+    from: rangeFrom,
+    to: rangeTo,
+  });
+
+  return (
+    <div className="min-h-screen bg-gray-50">
+      <Header user={toPublicUser(user)} />
+      <ProjectNav projectId={project.id} active="calendar" />
+      <main className="mx-auto max-w-3xl space-y-6 p-6">
+        <h1 className="text-2xl font-bold">カレンダー</h1>
+        <p className="text-sm text-gray-500">
+          期間: {rangeFrom} 〜 {rangeTo}
+        </p>
+        <CalendarEventForm projectId={project.id} defaultDate={defaultFrom} />
+        <section className="space-y-2">
+          {events.length === 0 ? (
+            <p className="text-sm text-gray-400">
+              期間内のイベントはありません。
+            </p>
+          ) : (
+            events.map((e) => (
+              <div
+                key={e.key}
+                className="flex items-center justify-between rounded border bg-white p-3 shadow-sm"
+                data-testid={`calendar-event-${e.key}`}
+              >
+                <div>
+                  <p className="font-medium text-gray-800">{e.title}</p>
+                  <p className="text-xs text-gray-400">{e.startAt}</p>
+                </div>
+                <span
+                  className={`rounded px-2 py-0.5 text-xs ${
+                    SOURCE_COLORS[e.source] ?? 'bg-gray-100 text-gray-600'
+                  }`}
+                >
+                  {e.source}
+                </span>
+              </div>
+            ))
+          )}
+        </section>
+      </main>
+    </div>
+  );
+}

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

@@ -0,0 +1,93 @@
+import { redirect } from 'next/navigation';
+import { getCurrentUser, toPublicUser } from '@/lib/auth/getCurrentUser';
+import {
+  createScheduleService,
+  createProjectService,
+} from '@/lib/api/services';
+import { Header } from '@/components/layout/Header';
+import { ProjectNav } from '@/components/layout/ProjectNav';
+import { MilestoneForm } from '@/components/calendar/MilestoneForm';
+import { ForbiddenError, NotFoundError } from '@/lib/errors';
+
+export const dynamic = 'force-dynamic';
+
+function progressColor(progress: number): string {
+  if (progress >= 67) return 'bg-green-500';
+  if (progress >= 34) return 'bg-yellow-500';
+  return 'bg-red-500';
+}
+
+export default async function MilestonesPage({
+  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 scheduleService = createScheduleService();
+  const milestones = scheduleService.getMilestones(user.id, project.id);
+
+  return (
+    <div className="min-h-screen bg-gray-50">
+      <Header user={toPublicUser(user)} />
+      <ProjectNav projectId={project.id} active="milestones" />
+      <main className="mx-auto max-w-3xl space-y-6 p-6">
+        <h1 className="text-2xl font-bold">マイルストーン</h1>
+        <MilestoneForm projectId={project.id} />
+        <section className="space-y-3">
+          {milestones.length === 0 ? (
+            <p className="text-sm text-gray-400">
+              マイルストーンはありません。
+            </p>
+          ) : (
+            milestones.map((m) => (
+              <div
+                key={m.id}
+                className="rounded-lg border bg-white p-4 shadow-sm"
+                data-testid={`milestone-${m.id}`}
+              >
+                <div className="flex items-center justify-between">
+                  <h3 className="font-semibold text-gray-800">{m.title}</h3>
+                  <span className="text-xs text-gray-500">
+                    {m.status}
+                    {m.dueDate ? ` / 期限: ${m.dueDate}` : ''}
+                  </span>
+                </div>
+                {m.description && (
+                  <p className="mt-1 text-sm text-gray-600">{m.description}</p>
+                )}
+                <div className="mt-3">
+                  <div className="flex items-center justify-between text-xs text-gray-500">
+                    <span>進捗</span>
+                    <span data-testid={`milestone-progress-${m.id}`}>
+                      {m.progress}%
+                    </span>
+                  </div>
+                  <div className="mt-1 h-2 w-full rounded bg-gray-200">
+                    <div
+                      className={`h-2 rounded ${progressColor(m.progress)}`}
+                      style={{ width: `${m.progress}%` }}
+                    />
+                  </div>
+                </div>
+              </div>
+            ))
+          )}
+        </section>
+      </main>
+    </div>
+  );
+}