Add group list view

Sources/Photochk/Views/GroupListView.swift

@@ -0,0 +1,114 @@
+import SwiftUI
+
+struct GroupListView: View {
+    @Bindable var model: ScanViewModel
+
+    var body: some View {
+        List(selection: $model.selectedGroupID) {
+            if !model.groups.isEmpty {
+                Section {
+                    ForEach(model.groups) { group in
+                        GroupRow(group: group, markedCount: markedCount(in: group))
+                            .tag(group.id)
+                    }
+                } header: {
+                    Text("\(model.groups.count) グループ・重複 \(model.totalDuplicateCount) 枚")
+                }
+            }
+        }
+        .listStyle(.sidebar)
+        .overlay {
+            if model.groups.isEmpty && !model.isScanning {
+                sidebarPlaceholder
+            }
+        }
+        .safeAreaInset(edge: .bottom) {
+            if !model.groups.isEmpty {
+                summaryBar
+            }
+        }
+    }
+
+    private func markedCount(in group: SimilarityGroup) -> Int {
+        group.members.filter { model.markedForDeletion.contains($0.id) }.count
+    }
+
+    private var sidebarPlaceholder: some View {
+        VStack(spacing: 6) {
+            if model.folder == nil {
+                Text("フォルダが未選択です")
+            } else if model.hasScanned {
+                Text("似た写真は見つかりませんでした")
+            } else {
+                Text("スキャンしていません")
+            }
+        }
+        .font(.callout)
+        .foregroundStyle(.secondary)
+        .padding()
+    }
+
+    private var summaryBar: some View {
+        VStack(alignment: .leading, spacing: 2) {
+            Divider()
+            Text("最大 \(model.totalReclaimableText) 削減できます")
+                .font(.callout)
+            if model.markedCount > 0 {
+                Text("\(model.markedCount) 枚を選択中（\(model.markedBytesText)）")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+            }
+        }
+        .frame(maxWidth: .infinity, alignment: .leading)
+        .padding(.horizontal, 12)
+        .padding(.bottom, 8)
+        .background(.bar)
+    }
+}
+
+struct GroupRow: View {
+    let group: SimilarityGroup
+    let markedCount: Int
+
+    var body: some View {
+        HStack(spacing: 10) {
+            ThumbnailView(url: group.representativeID, size: 52)
+
+            VStack(alignment: .leading, spacing: 3) {
+                Text(group.representative.fileName)
+                    .lineLimit(1)
+                    .truncationMode(.middle)
+
+                HStack(spacing: 6) {
+                    Text(group.kindText)
+                        .font(.caption2)
+                        .padding(.horizontal, 5)
+                        .padding(.vertical, 1)
+                        .background(
+                            group.isAllExact ? Color.orange.opacity(0.22) : Color.accentColor.opacity(0.18),
+                            in: Capsule()
+                        )
+                    Text("\(group.members.count) 枚")
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+                }
+
+                Text("\(group.reclaimableBytesText) 削減可")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+            }
+
+            Spacer(minLength: 0)
+
+            if markedCount > 0 {
+                Text("\(markedCount)")
+                    .font(.caption.monospacedDigit())
+                    .foregroundStyle(.white)
+                    .padding(.horizontal, 6)
+                    .padding(.vertical, 2)
+                    .background(Color.red, in: Capsule())
+            }
+        }
+        .padding(.vertical, 3)
+    }
+}