```

refactor: 重命名项目名称从"体己"到"康康"

将整个项目的目录结构从"体己"重命名为"康康"，包括所有源代码文件、
资源文件、测试文件以及Xcode项目配置文件。此更改涉及项目中所有的
文件路径和应用入口点(App/TijiApp.swift → App/KangkangApp.swift)。
```

康康/RootView.swift

@@ -0,0 +1,151 @@
+import SwiftUI
+
+enum TjTab: String, Hashable, CaseIterable {
+    case home, trend, me
+    var label: String {
+        switch self {
+        case .home:  return "首页"
+        case .trend: return "趋势"
+        case .me:    return "我的"
+        }
+    }
+    var icon: String {
+        switch self {
+        case .home:  return "house"
+        case .trend: return "chart.line.uptrend.xyaxis"
+        case .me:    return "person.circle"
+        }
+    }
+}
+
+enum ActiveFlow: Identifiable {
+    case quick, archive
+    var id: String { String(describing: self) }
+}
+
+struct RootView: View {
+    @State private var tab: TjTab = .home
+    @State private var showRecordSheet = false
+    @State private var activeFlow: ActiveFlow?
+
+    var body: some View {
+        VStack(spacing: 0) {
+            Group {
+                switch tab {
+                case .home:  HomeView(onTapArchive: {})
+                case .trend: TrendsView()
+                case .me:    MeView()
+                }
+            }
+            .frame(maxWidth: .infinity, maxHeight: .infinity)
+
+            TabBar(active: tab,
+                   onTap: { tab = $0 },
+                   onTapRecord: { showRecordSheet = true })
+        }
+        .background(Tj.Palette.sand.ignoresSafeArea())
+        .sheet(isPresented: $showRecordSheet) {
+            RecordSheet { kind in
+                showRecordSheet = false
+                DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
+                    switch kind {
+                    case .quick:   activeFlow = .quick
+                    case .archive: activeFlow = .archive
+                    case .diary:   break
+                    }
+                }
+            }
+        }
+#if os(iOS)
+        .fullScreenCover(item: $activeFlow) { flow in
+            switch flow {
+            case .quick:
+                QuickCaptureFlow(onClose: { activeFlow = nil })
+            case .archive:
+                ArchiveFlow(onClose: { activeFlow = nil })
+            }
+        }
+#else
+        .sheet(item: $activeFlow) { flow in
+            switch flow {
+            case .quick:
+                QuickCaptureFlow(onClose: { activeFlow = nil })
+            case .archive:
+                ArchiveFlow(onClose: { activeFlow = nil })
+            }
+        }
+#endif
+    }
+}
+
+private struct TabBar: View {
+    let active: TjTab
+    let onTap: (TjTab) -> Void
+    let onTapRecord: () -> Void
+
+    var body: some View {
+        HStack(spacing: 0) {
+            tabItem(.home)
+            Color.clear.frame(width: 60, height: 1)
+            tabItem(.trend)
+            tabItem(.me)
+        }
+        .padding(.horizontal, 12)
+        .padding(.top, 10)
+        .padding(.bottom, 4)
+        .background(
+            Tj.Palette.paper
+                .overlay(alignment: .top) {
+                    Rectangle()
+                        .fill(Tj.Palette.lineSoft)
+                        .frame(height: 1)
+                }
+        )
+        .overlay(alignment: .top) {
+            recordButton.offset(y: -22)
+        }
+    }
+
+    private func tabItem(_ t: TjTab) -> some View {
+        Button { onTap(t) } label: {
+            VStack(spacing: 4) {
+                Image(systemName: t.icon)
+                    .font(.system(size: 20, weight: .regular))
+                    .frame(width: 26, height: 26)
+                Text(t.label)
+                    .font(.system(size: 11))
+            }
+            .foregroundStyle(active == t ? Tj.Palette.ink : Tj.Palette.text3)
+            .frame(maxWidth: .infinity)
+            .padding(.vertical, 4)
+            .contentShape(Rectangle())
+        }
+        .buttonStyle(.plain)
+    }
+
+    private var recordButton: some View {
+        Button(action: onTapRecord) {
+            VStack(spacing: 4) {
+                ZStack {
+                    Circle()
+                        .fill(Tj.Palette.ink)
+                        .shadow(color: Color(red: 0.157, green: 0.216, blue: 0.176).opacity(0.25),
+                                radius: 12, x: 0, y: 4)
+                    Image(systemName: "plus")
+                        .font(.system(size: 20, weight: .semibold))
+                        .foregroundStyle(Tj.Palette.paper)
+                }
+                .frame(width: 52, height: 52)
+
+                Text("记录")
+                    .font(.system(size: 11))
+                    .foregroundStyle(Tj.Palette.ink)
+            }
+        }
+        .buttonStyle(.plain)
+    }
+}
+
+#Preview {
+    RootView()
+}