feat(Trends): AI 趋势解读上线 — 数据指纹缓存,秒开不重算

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

康康/Features/Trends/TrendDetailView.swift

@@ -69,7 +69,7 @@ struct TrendDetailView: View {
                 }
                 chartCard
                 statsCard
-                aiPlaceholder
+                TrendInsightCard(bucket: bucket)
                 pointsList
             }
             .padding(.horizontal, 20)
@@ -318,27 +318,6 @@ struct TrendDetailView: View {
         return ("\(arrow) \(fmt(abs(d)))\(pctStr)", color)
     }
 
-    // MARK: AI 解读占位
-
-    private var aiPlaceholder: some View {
-        HStack(spacing: 8) {
-            Image(systemName: "sparkles")
-                .font(.tjScaled( 12))
-                .foregroundStyle(Tj.Palette.text3)
-            Text("AI 趋势解读即将上线")
-                .font(.tjScaled( 12))
-                .foregroundStyle(Tj.Palette.text3)
-            Spacer()
-        }
-        .padding(.horizontal, 14)
-        .padding(.vertical, 12)
-        .frame(maxWidth: .infinity, alignment: .leading)
-        .background(
-            RoundedRectangle(cornerRadius: Tj.Radius.sm, style: .continuous)
-                .fill(Tj.Palette.sand2.opacity(0.6))
-        )
-    }
-
     // MARK: 数据点列表
 
     /// 跨线按天合并:每天一行,展示该天各线的值。倒序。
@@ -423,6 +402,80 @@ struct TrendDetailView: View {
     }
 }
 
+// MARK: - AI 趋势解读卡
+
+/// 进入页面先查指纹缓存:命中秒显;未命中本地现算(经 TrendInsightService,§3.1)。
+private struct TrendInsightCard: View {
+    let bucket: SeriesBucket
+    @State private var text: String?
+    @State private var running = false
+    @State private var failedMessage: String?
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            HStack(spacing: 6) {
+                Image(systemName: "sparkles")
+                    .font(.tjScaled( 12))
+                    .foregroundStyle(Tj.Palette.ink)
+                Text("AI 解读")
+                    .font(.tjScaled( 12, weight: .semibold))
+                    .foregroundStyle(Tj.Palette.text2)
+                Spacer()
+            }
+            if let text {
+                Text(text)
+                    .font(.tjScaled( 13))
+                    .lineSpacing(3)
+                    .foregroundStyle(Tj.Palette.text)
+                    .fixedSize(horizontal: false, vertical: true)
+                AIDisclaimerFooter()
+            } else if running {
+                Text("本地 AI 解读中…")
+                    .font(.tjScaled( 12))
+                    .foregroundStyle(Tj.Palette.text3)
+                AIFlowBar()
+            } else if let failedMessage {
+                HStack {
+                    Text(failedMessage)
+                        .font(.tjScaled( 12))
+                        .foregroundStyle(Tj.Palette.text3)
+                    Spacer()
+                    Button("重试") { Task { await load(force: true) } }
+                        .font(.tjScaled( 12, weight: .medium))
+                        .foregroundStyle(Tj.Palette.ink)
+                }
+            }
+        }
+        .padding(14)
+        .frame(maxWidth: .infinity, alignment: .leading)
+        .background(
+            RoundedRectangle(cornerRadius: Tj.Radius.md, style: .continuous)
+                .fill(Tj.Palette.paper)
+        )
+        .overlay(
+            RoundedRectangle(cornerRadius: Tj.Radius.md, style: .continuous)
+                .strokeBorder(Tj.Palette.lineSoft, lineWidth: 1)
+        )
+        .task(id: bucket.id) { await load(force: false) }
+    }
+
+    @MainActor
+    private func load(force: Bool) async {
+        if !force, let cached = TrendInsightService.shared.cachedText(for: bucket) {
+            text = cached
+            return
+        }
+        running = true
+        failedMessage = nil
+        do {
+            text = try await TrendInsightService.shared.generate(for: bucket)
+        } catch {
+            failedMessage = String(appLoc: "AI 解读暂不可用(模型未就绪或繁忙)")
+        }
+        running = false
+    }
+}
+
 enum TrendRange: String, CaseIterable, Identifiable {
     case all, year, sixMonths, threeMonths
     var id: String { rawValue }