feat(ios): IOS-M0-05 Learning Activity 学习统计详情

- ActivityService 新增 trend()/streak()/recommendations()
- ActivityViewModel 加载连续学习/趋势/推荐数据
- AnalysisHomeView 新增连续学习卡片（火焰+天数+最长记录）
- AnalysisHomeView 新增学习推荐列表（type图标+标题+优先级标签）

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

AIStudyApp/AIStudyApp/Core/Models/APIModels.swift

@@ -493,6 +493,28 @@ struct AddSourceRequest: Codable {
     let title: String?
 }
 
+// MARK: - Learning Activity
+
+struct ActivityTrend: Codable {
+    let date: String?
+    let value: Double?
+    let label: String?
+}
+
+struct ActivityStreak: Codable {
+    let currentStreak: Int?
+    let longestStreak: Int?
+    let lastActiveDate: String?
+}
+
+struct ActivityRecommendation: Codable, Identifiable {
+    var id: String { title ?? UUID().uuidString }
+    let title: String?
+    let description: String?
+    let type: String?
+    let priority: String?
+}
+
 // MARK: - File Upload (COS presigned URL flow)
 
 struct FileUploadUrlRequest: Codable {

AIStudyApp/AIStudyApp/Core/Services/APIService.swift

@@ -258,6 +258,18 @@ class ActivityService {
     func heatmap() async throws -> [String: Int] {
         return try await client.request("/activity/heatmap")
     }
+
+    func trend(days: Int = 7) async throws -> [ActivityTrend] {
+        return try await client.request("/activity/trend?days=\(days)")
+    }
+
+    func streak() async throws -> ActivityStreak {
+        return try await client.request("/activity/streak")
+    }
+
+    func recommendations() async throws -> [ActivityRecommendation] {
+        return try await client.request("/activity/recommendations")
+    }
 }
 
 // MARK: - Feedback

AIStudyApp/AIStudyApp/Features/Analysis/ActivityViewModel.swift

@@ -6,6 +6,9 @@ class ActivityViewModel: ObservableObject {
     @Published var summary: ActivitySummary?
     @Published var focusItems: [FocusItem] = []
     @Published var heatmap: [String: Int] = [:]
+    @Published var streak: ActivityStreak?
+    @Published var trends: [ActivityTrend] = []
+    @Published var recommendations: [ActivityRecommendation] = []
     @Published var isLoading = false
     @Published var errorMessage: String?
 
@@ -16,10 +19,12 @@ class ActivityViewModel: ObservableObject {
             async let s = ActivityService.shared.summary()
             async let f = FocusItemService.shared.list()
             async let h = ActivityService.shared.heatmap()
-            let (summaryResult, focusResult, heatmapResult) = try await (s, f, h)
+            async let st = ActivityService.shared.streak()
-            summary = summaryResult
+            async let t = ActivityService.shared.trend()
-            focusItems = focusResult
+            async let r = ActivityService.shared.recommendations()
-            heatmap = heatmapResult
+            let (summaryResult, focusResult, heatmapResult, streakResult, trendResult, recResult) = try await (s, f, h, st, t, r)
+            summary = summaryResult; focusItems = focusResult; heatmap = heatmapResult
+            streak = streakResult; trends = trendResult; recommendations = recResult
         } catch {
             if summary == nil { errorMessage = "加载分析数据失败" }
         }
@@ -31,10 +36,12 @@ class ActivityViewModel: ObservableObject {
             async let s = ActivityService.shared.summary()
             async let f = FocusItemService.shared.list()
             async let h = ActivityService.shared.heatmap()
-            let (summaryResult, focusResult, heatmapResult) = try await (s, f, h)
+            async let st = ActivityService.shared.streak()
-            summary = summaryResult
+            async let t = ActivityService.shared.trend()
-            focusItems = focusResult
+            async let r = ActivityService.shared.recommendations()
-            heatmap = heatmapResult
+            let (summaryResult, focusResult, heatmapResult, streakResult, trendResult, recResult) = try await (s, f, h, st, t, r)
+            summary = summaryResult; focusItems = focusResult; heatmap = heatmapResult
+            streak = streakResult; trends = trendResult; recommendations = recResult
         } catch {}
     }
 }

AIStudyApp/AIStudyApp/Features/Analysis/AnalysisHomeView.swift

@@ -39,6 +39,31 @@ struct AnalysisHomeView: View {
                             }
                         }.padding(16).background(Color.zxFill004).overlay(RoundedRectangle(cornerRadius: 20).stroke(Color.zxBorder006, lineWidth: 1)).clipShape(RoundedRectangle(cornerRadius: 20))
 
+                        if let streak = viewModel.streak {
+                            HStack(spacing: 12) {
+                                ZXStatBadge(icon: "flame.fill", label: "连续学习", value: "\(streak.currentStreak ?? 0) 天", trend: "", color: Color.zxOrange)
+                                ZXStatBadge(icon: "trophy.fill", label: "最长连续", value: "\(streak.longestStreak ?? 0) 天", trend: "", color: Color.zxAmber)
+                                ZXStatBadge(icon: "calendar", label: "最后活跃", value: streak.lastActiveDate.flatMap { String($0.prefix(10)) } ?? "-", trend: "", color: Color.zxPrimary)
+                            }
+                        }
+                        if !viewModel.recommendations.isEmpty {
+                            VStack(alignment: .leading, spacing: 12) {
+                                Text("学习推荐").font(.system(size: 14, weight: .bold)).foregroundColor(Color.zxF0)
+                                ForEach(viewModel.recommendations.prefix(3)) { rec in
+                                    HStack(spacing: 10) {
+                                        Image(systemName: rec.type == "review" ? "arrow.triangle.2.circlepath" : "lightbulb.fill")
+                                            .font(.system(size: 14)).foregroundColor(Color.zxAccent)
+                                            .frame(width: 32, height: 32).background(Color.zxAccent.opacity(0.1)).clipShape(RoundedRectangle(cornerRadius: 8))
+                                        VStack(alignment: .leading, spacing: 2) {
+                                            Text(rec.title ?? "").font(.system(size: 13, weight: .semibold)).foregroundColor(Color.zxF0)
+                                            if let desc = rec.description { Text(desc).font(.system(size: 11)).foregroundColor(Color.zxF04).lineLimit(1) }
+                                        }
+                                        Spacer()
+                                        if let p = rec.priority { Text(p).font(.system(size: 10, weight: .bold)).foregroundColor(p == "high" ? Color.zxCoral : Color.zxAmber).padding(.horizontal, 6).padding(.vertical, 2).background((p == "high" ? Color.zxCoral : Color.zxAmber).opacity(0.1)).clipShape(Capsule()) }
+                                    }.padding(10).background(Color.zxFill003).clipShape(RoundedRectangle(cornerRadius: 12))
+                                }
+                            }.padding(16).background(Color.zxFill004).overlay(RoundedRectangle(cornerRadius: 20).stroke(Color.zxBorder006, lineWidth: 1)).clipShape(RoundedRectangle(cornerRadius: 20))
+                        }
                         VStack(alignment: .leading, spacing: 12) {
                             HStack { HStack(spacing: 8) { Image(systemName: "exclamationmark.triangle.fill").font(.system(size: 14)).foregroundColor(Color.zxYellow); Text("薄弱知识点").font(.system(size: 15, weight: .bold)).foregroundColor(Color.zxF0) }; Spacer(); NavigationLink(value: Route.weakPoints) { Text("全部 \(viewModel.focusItems.count) 个").font(.system(size: 12)).foregroundColor(Color.zxPurple) }.accessibilityLabel("查看全部薄弱知识点") }
                             ForEach(viewModel.focusItems.prefix(5)) { item in