chore(preview): add #Preview to RecordSheet + DebugAIRunner

之前 HomeView/MeView/TrendsView/ArchiveListView/RootView/SymptomStartSheet
都有 #Preview,只剩这两个。补完后所有主屏 View 都能在 Xcode Canvas 直接
预览,改 UI 不用 build & run。

康康/Debug/DebugAIRunner.swift

@@ -200,4 +200,12 @@ struct DebugAIRunner: View {
         refreshModelStatus()
     }
 }
+
+#Preview("DebugAIRunner") {
+    ScrollView {
+        DebugAIRunner()
+            .padding(.vertical, 24)
+    }
+    .background(Tj.Palette.sand.ignoresSafeArea())
+}
 #endif

康康/Features/Record/RecordSheet.swift

@@ -108,3 +108,26 @@ struct RecordSheet: View {
         .presentationCornerRadius(Tj.Radius.xl)
     }
 }
+
+#Preview("RecordSheet · 直接渲染") {
+    RecordSheet { kind in print("picked: \(kind)") }
+        .frame(width: 390, height: 560)
+        .background(Tj.Palette.sand)
+}
+
+#Preview("RecordSheet · sheet 模式") {
+    PreviewContainer()
+}
+
+private struct PreviewContainer: View {
+    @State private var show = true
+    var body: some View {
+        Text("点这里再开一次")
+            .onTapGesture { show = true }
+            .frame(maxWidth: .infinity, maxHeight: .infinity)
+            .background(Tj.Palette.sand.ignoresSafeArea())
+            .sheet(isPresented: $show) {
+                RecordSheet { kind in print("picked: \(kind)"); show = false }
+            }
+    }
+}