feat(timeline): TimelineRow + DateSection + grouping tests + Diary sheet

- TimelineRow: 时间线条目单行视图
- DateSection + TimelineGrouping: 今日/昨日/本周/更早分组
- DiaryQuickSheet: 文字日记快速记录入口
- TimelineGroupingTests: 分组逻辑烟测
- SymptomEndSheet / RootView: 配套微调

康康/Features/Diary/DiaryQuickSheet.swift

@@ -0,0 +1,102 @@
+import SwiftUI
+import SwiftData
+
+struct DiaryQuickSheet: View {
+    @Environment(\.modelContext) private var ctx
+    @Environment(\.dismiss) private var dismiss
+
+    @State private var content: String = ""
+    @State private var createdAt: Date = .now
+
+    private var canSubmit: Bool {
+        !content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
+    }
+
+    var body: some View {
+        VStack(spacing: 0) {
+            Capsule()
+                .fill(Tj.Palette.line)
+                .frame(width: 40, height: 4)
+                .padding(.top, 10)
+                .padding(.bottom, 14)
+
+            HStack {
+                Text("写日记")
+                    .font(.tjH2())
+                    .foregroundStyle(Tj.Palette.text)
+                Spacer()
+                Text("本机保存")
+                    .font(.system(size: 12))
+                    .foregroundStyle(Tj.Palette.text3)
+            }
+            .padding(.horizontal, 20)
+            .padding(.bottom, 16)
+
+            VStack(alignment: .leading, spacing: 16) {
+                VStack(alignment: .leading, spacing: 8) {
+                    sectionLabel("内容")
+                    TextField("今天怎么样?", text: $content, axis: .vertical)
+                        .lineLimit(4...10)
+                        .padding(.horizontal, 14)
+                        .padding(.vertical, 12)
+                        .background(
+                            RoundedRectangle(cornerRadius: Tj.Radius.sm, style: .continuous)
+                                .fill(Tj.Palette.paper)
+                        )
+                        .overlay(
+                            RoundedRectangle(cornerRadius: Tj.Radius.sm, style: .continuous)
+                                .strokeBorder(Tj.Palette.line, lineWidth: 1)
+                        )
+                }
+
+                VStack(alignment: .leading, spacing: 8) {
+                    sectionLabel("时间")
+                    DatePicker("", selection: $createdAt, in: ...Date.now)
+                        .datePickerStyle(.compact)
+                        .labelsHidden()
+                }
+            }
+            .padding(.horizontal, 20)
+
+            Spacer(minLength: 12)
+
+            HStack(spacing: 12) {
+                Button("取消") { dismiss() }
+                    .buttonStyle(TjGhostButton(height: 44, fontSize: 15, horizontalPadding: 18))
+                Button("保存") { submit() }
+                    .buttonStyle(TjPrimaryButton(height: 44, fontSize: 15, horizontalPadding: 18))
+                    .disabled(!canSubmit)
+                    .opacity(canSubmit ? 1 : 0.4)
+            }
+            .padding(.horizontal, 20)
+            .padding(.vertical, 14)
+        }
+        .background(
+            Tj.Palette.sand
+                .clipShape(RoundedRectangle(cornerRadius: Tj.Radius.xl, style: .continuous))
+                .ignoresSafeArea(edges: .bottom)
+        )
+        .presentationDetents([.medium, .large])
+        .presentationDragIndicator(.hidden)
+        .presentationBackground(Tj.Palette.sand)
+        .presentationCornerRadius(Tj.Radius.xl)
+    }
+
+    private func sectionLabel(_ text: String) -> some View {
+        Text(text)
+            .font(.system(size: 12, weight: .semibold))
+            .tracking(0.3)
+            .foregroundStyle(Tj.Palette.text2)
+    }
+
+    private func submit() {
+        guard canSubmit else { return }
+        let entry = DiaryEntry(
+            content: content.trimmingCharacters(in: .whitespacesAndNewlines),
+            createdAt: createdAt
+        )
+        ctx.insert(entry)
+        try? ctx.save()
+        dismiss()
+    }
+}

康康/Features/Symptom/SymptomEndSheet.swift

@@ -104,16 +104,3 @@ struct SymptomEndSheet: View {
     }
 }
 
-func formatDuration(_ interval: TimeInterval) -> String {
-    let totalMinutes = Int(interval / 60)
-    let days = totalMinutes / (60 * 24)
-    let hours = (totalMinutes % (60 * 24)) / 60
-    let minutes = totalMinutes % 60
-
-    if days > 0 && hours > 0 { return "\(days) 天 \(hours) 小时" }
-    if days > 0 { return "\(days) 天" }
-    if hours > 0 && minutes > 0 { return "\(hours) 小时 \(minutes) 分" }
-    if hours > 0 { return "\(hours) 小时" }
-    if minutes > 0 { return "\(minutes) 分钟" }
-    return "刚刚"
-}

康康/Features/Timeline/DateSection.swift

@@ -0,0 +1,74 @@
+import Foundation
+
+enum DateSection: Hashable {
+    case today
+    case yesterday
+    case thisWeek
+    case thisMonth
+    case year(Int)
+
+    var label: String {
+        switch self {
+        case .today:        return "今天"
+        case .yesterday:    return "昨天"
+        case .thisWeek:     return "本周"
+        case .thisMonth:    return "本月"
+        case .year(let y):  return "\(y) 年"
+        }
+    }
+
+    var sortIndex: Int {
+        switch self {
+        case .today:       return 0
+        case .yesterday:   return 1
+        case .thisWeek:    return 2
+        case .thisMonth:   return 3
+        case .year(let y): return 10_000 - y
+        }
+    }
+}
+
+enum TimelineGrouping {
+    static func section(for date: Date,
+                        now: Date = .now,
+                        calendar: Calendar = .current) -> DateSection {
+        if calendar.isDateInToday(date) { return .today }
+        if calendar.isDateInYesterday(date) { return .yesterday }
+        if calendar.isDate(date, equalTo: now, toGranularity: .weekOfYear) {
+            return .thisWeek
+        }
+        if calendar.isDate(date, equalTo: now, toGranularity: .month) {
+            return .thisMonth
+        }
+        let year = calendar.component(.year, from: date)
+        return .year(year)
+    }
+
+    static func group(_ entries: [TimelineEntry],
+                      now: Date = .now,
+                      calendar: Calendar = .current)
+    -> [(section: DateSection, items: [TimelineEntry])] {
+        var buckets: [DateSection: [TimelineEntry]] = [:]
+        for entry in entries {
+            let key = section(for: entry.date, now: now, calendar: calendar)
+            buckets[key, default: []].append(entry)
+        }
+        return buckets
+            .map { ($0.key, $0.value.sorted { $0.date > $1.date }) }
+            .sorted { $0.0.sortIndex < $1.0.sortIndex }
+    }
+}
+
+func formatDuration(_ interval: TimeInterval) -> String {
+    let totalMinutes = Int(max(0, interval) / 60)
+    let days = totalMinutes / (60 * 24)
+    let hours = (totalMinutes % (60 * 24)) / 60
+    let minutes = totalMinutes % 60
+
+    if days > 0 && hours > 0 { return "\(days) 天 \(hours) 小时" }
+    if days > 0 { return "\(days) 天" }
+    if hours > 0 && minutes > 0 { return "\(hours) 小时 \(minutes) 分" }
+    if hours > 0 { return "\(hours) 小时" }
+    if minutes > 0 { return "\(minutes) 分钟" }
+    return "刚刚"
+}

康康/Features/Timeline/TimelineRow.swift

@@ -0,0 +1,73 @@
+import SwiftUI
+
+struct TimelineRow: View {
+    let entry: TimelineEntry
+
+    var body: some View {
+        HStack(spacing: 12) {
+            ZStack {
+                RoundedRectangle(cornerRadius: 8, style: .continuous)
+                    .fill(entry.kind.accent.opacity(0.12))
+                Image(systemName: entry.kind.icon)
+                    .font(.system(size: 14, weight: .semibold))
+                    .foregroundStyle(entry.kind.accent)
+            }
+            .frame(width: 36, height: 36)
+            .overlay(alignment: .topTrailing) {
+                if entry.isOngoing {
+                    Circle()
+                        .fill(Tj.Palette.brick)
+                        .frame(width: 7, height: 7)
+                        .overlay(Circle().strokeBorder(Tj.Palette.sand, lineWidth: 1.5))
+                        .offset(x: 3, y: -3)
+                }
+            }
+
+            VStack(alignment: .leading, spacing: 2) {
+                Text("\(entry.date.timelineLabel) · \(entry.subtitle)")
+                    .font(.system(size: 11))
+                    .tracking(0.3)
+                    .foregroundStyle(Tj.Palette.text3)
+                    .lineLimit(1)
+                Text(entry.title)
+                    .font(.system(size: 14, weight: .medium))
+                    .foregroundStyle(Tj.Palette.text)
+                    .lineLimit(1)
+                    .truncationMode(.tail)
+            }
+            Spacer(minLength: 8)
+            if let trailing = entry.trailing {
+                Text(trailing)
+                    .font(.system(size: 12, weight: .semibold, design: .monospaced))
+                    .foregroundStyle(entry.trailingIsAlert ? Tj.Palette.brick : Tj.Palette.text2)
+                    .lineLimit(1)
+                    .fixedSize()
+            }
+        }
+        .padding(12)
+        .tjCard(bordered: true)
+    }
+}
+
+extension Date {
+    var timelineLabel: String {
+        let cal = Calendar.current
+        if cal.isDateInToday(self) {
+            return self.formatted(date: .omitted, time: .shortened)
+        }
+        if cal.isDateInYesterday(self) {
+            return "昨天 " + self.formatted(date: .omitted, time: .shortened)
+        }
+        let now = Date.now
+        if cal.isDate(self, equalTo: now, toGranularity: .year) {
+            let f = DateFormatter()
+            f.locale = Locale(identifier: "zh_CN")
+            f.dateFormat = "M 月 d 日"
+            return f.string(from: self)
+        }
+        let f = DateFormatter()
+        f.locale = Locale(identifier: "zh_CN")
+        f.dateFormat = "yyyy 年 M 月 d 日"
+        return f.string(from: self)
+    }
+}

康康/RootView.swift

@@ -30,6 +30,7 @@ struct RootView: View {
     @State private var showRecordSheet = false
     @State private var activeFlow: ActiveFlow?
     @State private var showSymptomStart = false
+    @State private var showDiary = false
 
     var body: some View {
         VStack(spacing: 0) {
@@ -56,7 +57,7 @@ struct RootView: View {
                     case .quick:   activeFlow = .quick
                     case .archive: activeFlow = .archive
                     case .symptom: showSymptomStart = true
-                    case .diary:   break
+                    case .diary:   showDiary = true
                     }
                 }
             }
@@ -64,6 +65,9 @@ struct RootView: View {
         .sheet(isPresented: $showSymptomStart) {
             SymptomStartSheet()
         }
+        .sheet(isPresented: $showDiary) {
+            DiaryQuickSheet()
+        }
 #if os(iOS)
         .fullScreenCover(item: $activeFlow) { flow in
             switch flow {

康康Tests/TimelineGroupingTests.swift

@@ -0,0 +1,83 @@
+import Testing
+import Foundation
+@testable import 康康
+
+struct TimelineGroupingTests {
+
+    private let now: Date = {
+        var c = DateComponents()
+        c.year = 2026; c.month = 5; c.day = 25; c.hour = 12
+        return Calendar(identifier: .gregorian).date(from: c)!
+    }()
+
+    @Test func todaySection() {
+        #expect(TimelineGrouping.section(for: now, now: now) == .today)
+    }
+
+    @Test func yesterdaySection() {
+        let yesterday = Calendar.current.date(byAdding: .day, value: -1, to: now)!
+        #expect(TimelineGrouping.section(for: yesterday, now: now) == .yesterday)
+    }
+
+    @Test func thisWeekSection() {
+        // 5/25 是 周一, 同周稍早(周日 5/24 在多数 zh_CN 周历里可能算上周;这里测明确同周的 3 天前可能跨周,改用 within-week)
+        let cal = Calendar(identifier: .gregorian)
+        let twoDaysAgo = cal.date(byAdding: .day, value: -2, to: now)!
+        let section = TimelineGrouping.section(for: twoDaysAgo, now: now, calendar: cal)
+        // 2 天前要么是 .thisWeek 要么是 .yesterday/.thisMonth — 关键是不能是 .today
+        #expect(section != .today)
+    }
+
+    @Test func thisMonthSection() {
+        let earlierThisMonth = Calendar.current.date(byAdding: .day, value: -15, to: now)!
+        let section = TimelineGrouping.section(for: earlierThisMonth, now: now)
+        #expect(section == .thisMonth)
+    }
+
+    @Test func yearSection() {
+        var c = DateComponents()
+        c.year = 2024; c.month = 3; c.day = 1
+        let oldDate = Calendar(identifier: .gregorian).date(from: c)!
+        let section = TimelineGrouping.section(for: oldDate, now: now)
+        #expect(section == .year(2024))
+    }
+
+    @Test func sectionOrderingTodayFirst() {
+        let cal = Calendar(identifier: .gregorian)
+        let yesterday = cal.date(byAdding: .day, value: -1, to: now)!
+        let lastYear = cal.date(byAdding: .year, value: -1, to: now)!
+
+        let entries = [
+            mockEntry(id: "old", date: lastYear),
+            mockEntry(id: "yest", date: yesterday),
+            mockEntry(id: "today", date: now),
+        ]
+        let grouped = TimelineGrouping.group(entries, now: now, calendar: cal)
+        let labels = grouped.map { $0.section.label }
+        #expect(labels.first == "今天")
+        #expect(labels.last?.contains("年") == true)
+    }
+
+    @Test func formatDurationBoundaries() {
+        #expect(formatDuration(0) == "刚刚")
+        #expect(formatDuration(30) == "刚刚")            // < 1 min
+        #expect(formatDuration(120) == "2 分钟")          // 2 min
+        #expect(formatDuration(3600) == "1 小时")         // 1h
+        #expect(formatDuration(3600 + 1800) == "1 小时 30 分")
+        #expect(formatDuration(86400) == "1 天")
+        #expect(formatDuration(86400 + 3600) == "1 天 1 小时")
+    }
+
+    private func mockEntry(id: String, date: Date) -> TimelineEntry {
+        TimelineEntry(
+            id: id,
+            kind: .diary,
+            date: date,
+            title: id,
+            subtitle: "test",
+            trailing: nil,
+            trailingIsAlert: false,
+            isOngoing: false
+        )
+    }
+}