カレンダーイベント管理アプリの最初のプロジェクト構成と基本実装

- .gitignore や project.yml、Makefile などによる基本的なプロジェクト構成ファイルを追加
- macOSカレンダーイベントを表示するSwiftUIアプリの主要コンポーネント（イベント取得・リスト・カレンダー設定画面など）を実装
- カレンダーの表示期間や「今日へスクロール」「設定画面」遷移などの基本動作に対応

Sources/ContentView.swift

@@ -0,0 +1,164 @@
+import SwiftUI
+import EventKit
+
+struct ContentView: View {
+    @StateObject private var calendarService = CalendarService()
+    @State private var scrollToToday = false
+    @State private var showingSettings = false
+
+    var body: some View {
+        VStack(spacing: 0) {
+            if calendarService.hasAccess {
+                ScrollViewReader { proxy in
+                    List {
+                        ForEach(groupedEventsByDay(), id: \.date) { dayGroup in
+                            Section(header: dayHeader(for: dayGroup.date)) {
+                                ForEach(dayGroup.events, id: \.eventIdentifier) { event in
+                                    EventRow(event: event)
+                                }
+                            }
+                            .id(dayGroup.date)
+                        }
+                    }
+                    .listStyle(.plain)
+                    .onAppear {
+                        if !scrollToToday {
+                            let today = Calendar.current.startOfDay(for: Date())
+                            proxy.scrollTo(today, anchor: .top)
+                            scrollToToday = true
+                        }
+                    }
+                    .onChange(of: scrollToToday) { _, newValue in
+                        if newValue {
+                            let today = Calendar.current.startOfDay(for: Date())
+                            withAnimation {
+                                proxy.scrollTo(today, anchor: .top)
+                            }
+                            scrollToToday = false
+                        }
+                    }
+                }
+            } else {
+                VStack {
+                    Text("カレンダーへのアクセス権限が必要です")
+                        .font(.headline)
+                    Text("システム設定からアクセスを許可してください")
+                        .font(.subheadline)
+                        .foregroundColor(.secondary)
+                }
+                .padding()
+            }
+        }
+        .sheet(isPresented: $showingSettings) {
+            SettingsView(calendarService: calendarService)
+        }
+        .toolbar {
+            ToolbarItem(placement: .primaryAction) {
+                Button(action: {
+                    showingSettings = true
+                }) {
+                    Label("設定", systemImage: "gearshape")
+                }
+            }
+            ToolbarItem(placement: .primaryAction) {
+                Button(action: {
+                    scrollToToday = true
+                }) {
+                    Label("今日", systemImage: "calendar")
+                }
+            }
+        }
+    }
+
+    private func groupedEventsByDay() -> [DayGroup] {
+        let calendar = Calendar.current
+        let grouped = Dictionary(grouping: calendarService.events) { event in
+            calendar.startOfDay(for: event.startDate)
+        }
+
+        let today = calendar.startOfDay(for: Date())
+        guard let startDate = calendar.date(byAdding: .day, value: -14, to: today),
+              let endDate = calendar.date(byAdding: .day, value: 14, to: today) else {
+            return []
+        }
+
+        var allDates: [Date] = []
+        var currentDate = startDate
+        while currentDate <= endDate {
+            allDates.append(currentDate)
+            guard let nextDate = calendar.date(byAdding: .day, value: 1, to: currentDate) else { break }
+            currentDate = nextDate
+        }
+
+        return allDates.map { date in
+            DayGroup(date: date, events: grouped[date] ?? [])
+        }.sorted { $0.date < $1.date }
+    }
+
+    private func dayHeader(for date: Date) -> some View {
+        let calendar = Calendar.current
+        let isToday = calendar.isDateInToday(date)
+        let formatter = DateFormatter()
+        formatter.dateFormat = "M月d日(E)"
+        formatter.locale = Locale(identifier: "ja_JP")
+
+        return HStack {
+            Text(formatter.string(from: date))
+                .font(.headline)
+                .foregroundColor(isToday ? .blue : .primary)
+            if isToday {
+                Text("今日")
+                    .font(.caption)
+                    .padding(.horizontal, 6)
+                    .padding(.vertical, 2)
+                    .background(Color.blue)
+                    .foregroundColor(.white)
+                    .cornerRadius(4)
+            }
+        }
+    }
+}
+
+struct DayGroup {
+    let date: Date
+    let events: [EKEvent]
+}
+
+struct EventRow: View {
+    let event: EKEvent
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 4) {
+            HStack {
+                if event.isAllDay {
+                    Text("終日")
+                        .font(.caption)
+                        .foregroundColor(.secondary)
+                } else {
+                    Text(timeString(from: event.startDate, to: event.endDate))
+                        .font(.caption)
+                        .foregroundColor(.secondary)
+                }
+                if let calendar = event.calendar {
+                    Circle()
+                        .fill(Color(calendar.color))
+                        .frame(width: 8, height: 8)
+                }
+            }
+            Text(event.title ?? "無題のイベント")
+                .font(.body)
+            if let location = event.location, !location.isEmpty {
+                Text(location)
+                    .font(.caption)
+                    .foregroundColor(.secondary)
+            }
+        }
+        .padding(.vertical, 4)
+    }
+
+    private func timeString(from start: Date, to end: Date) -> String {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "HH:mm"
+        return "\(formatter.string(from: start)) - \(formatter.string(from: end))"
+    }
+}