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

tests/unit/repositories/MilestoneRepository.test.ts

@@ -0,0 +1,84 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { createMigratedTestDb } from '@/tests/helpers/db';
+import type { SqliteDatabase } from '@/lib/db/sqlite';
+import { UserRepository } from '@/repositories/UserRepository';
+import { ProjectRepository } from '@/repositories/ProjectRepository';
+import { ProjectMemberRepository } from '@/repositories/ProjectMemberRepository';
+import { TodoRepository } from '@/repositories/TodoRepository';
+import { MilestoneRepository } from '@/repositories/MilestoneRepository';
+
+describe('MilestoneRepository', () => {
+  let db: SqliteDatabase;
+  let repo: MilestoneRepository;
+  let todoRepo: TodoRepository;
+  let projectId: number;
+  let userId: number;
+  let columnId: number;
+
+  beforeEach(() => {
+    db = createMigratedTestDb();
+    repo = new MilestoneRepository(db);
+    todoRepo = new TodoRepository(db);
+    userId = new UserRepository(db).create({
+      name: 'U',
+      email: 'u@example.com',
+      passwordHash: 'h',
+    }).id;
+    projectId = new ProjectRepository(db).create({
+      name: 'P',
+      ownerId: userId,
+    }).id;
+    new ProjectMemberRepository(db).add(projectId, userId, 'admin');
+    columnId = todoRepo.createColumn({
+      projectId,
+      name: 'Todo',
+      orderIndex: 0,
+    }).id;
+  });
+
+  afterEach(() => db.close());
+
+  it('creates and lists milestones ordered by due_date', () => {
+    repo.create({ projectId, title: 'M2', dueDate: '2026-12-31' });
+    repo.create({ projectId, title: 'M1', dueDate: '2026-06-30' });
+    const list = repo.findByProject(projectId);
+    expect(list.map((m) => m.title)).toEqual(['M1', 'M2']);
+  });
+
+  it('updates and deletes a milestone', () => {
+    const m = repo.create({ projectId, title: 'M' });
+    expect(repo.update(m.id, { status: 'closed' })?.status).toBe('closed');
+    repo.delete(m.id);
+    expect(repo.findById(m.id)).toBeNull();
+  });
+
+  it('excludes soft-deleted milestones', () => {
+    const m = repo.create({ projectId, title: 'M' });
+    repo.delete(m.id);
+    expect(repo.findByProject(projectId)).toHaveLength(0);
+  });
+
+  it('findToDosByMilestone returns only linked, non-deleted todos', () => {
+    const m = repo.create({ projectId, title: 'M' });
+    const t1 = todoRepo.createItem({
+      projectId,
+      columnId,
+      title: 't1',
+      creatorId: userId,
+      orderIndex: 0,
+    });
+    const t2 = todoRepo.createItem({
+      projectId,
+      columnId,
+      title: 't2',
+      creatorId: userId,
+      orderIndex: 1,
+    });
+    todoRepo.updateItem(t1.id, { milestoneId: m.id });
+    todoRepo.updateItem(t2.id, { milestoneId: m.id });
+    todoRepo.deleteItem(t2.id); // soft delete
+    const todos = repo.findToDosByMilestone(m.id);
+    expect(todos).toHaveLength(1);
+    expect(todos[0].id).toBe(t1.id);
+  });
+});