feat(ui): UI 骨架基线 — 3 Tab + RecordSheet + Quick/Archive 流程占位

替换 Xcode 默认模板:
- 删除 ContentView/Item/__App
- 新增 App/TijiApp(SwiftData ModelContainer)、RootView(3 Tab + RecordSheet)
- DesignSystem:Tokens(色板/字体/圆角)+ Components(卡片/按钮/Chip)
- Models:Indicator / Report / DiaryEntry @Model 初版
- Features:Home / Quick(A1-A3)/ Archive(B1-B5)/ Record / Trends / Me 静态 UI

W2 AI 基座工作将在此基线上叠加。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

体己/Features/Trends/TrendsView.swift

@@ -0,0 +1,19 @@
+import SwiftUI
+
+struct TrendsView: View {
+    var body: some View {
+        VStack(spacing: 12) {
+            Spacer()
+            TjPlaceholder(label: "trends · 折线图 + 影像档案入口\n（尚未实现）")
+                .frame(width: 280, height: 180)
+            Text("趋势")
+                .font(.tjH2())
+                .foregroundStyle(Tj.Palette.text2)
+            Spacer()
+        }
+        .frame(maxWidth: .infinity, maxHeight: .infinity)
+        .background(Tj.Palette.sand.ignoresSafeArea())
+    }
+}
+
+#Preview { TrendsView() }