fix(core): 代码审查修复 AI 并发/隐私/解析等多处缺陷

- AIRuntime 加 actor 内串行推理闸门,封死 LLM/VL in-flight 并发解码窄口(jetsam OOM 根因)
- prepare 的 .loading 改轮询等待消除假就绪竞态;就绪判据 isReady→isComplete 防半下载崩溃
- applyReanalyzed 重新解读时 unlink 旧 Asset,消除 Vault 孤儿图片(§6 隐私承诺)
- parseReportJSON 改 extractBalancedJSON + 裸数组兜底,防 VL 多项输出被静默截断丢指标
- 临时文件改 completeUnlessOpen 修锁屏写失败;parseDate 支持多格式防归档年份错位
- TimelineEntry/DayDetailSheet 修「偏高」文案与血压箭头方向(偏低指标不再显示相反结论)
- FileVault.wipe 容错;HealthExportSheet 异常关键词排除否定句;modelTag 取实际枚举值
- 删除 B1-B5 + ArchiveFlow 死代码(含违反 §6 的 AES 加密文案)
- 补 3 个回归测试,编译 + 测试全部通过

康康/Features/Timeline/TimelineEntry.swift

@@ -86,32 +86,52 @@ struct TimelineEntry: Identifiable, Hashable {
 
     private static func mergedBP(systolic sys: Indicator, diastolic dia: Indicator) -> TimelineEntry {
         let abnormal = sys.status != .normal || dia.status != .normal
+        // 方向箭头按实际 status 给:两值同向才标 ↑/↓;一高一低只标红不给方向
+        // (旧实现异常一律 ↑,低血压 85/55 会错误显示 ↑)。
+        let arrow: String
+        switch (sys.status, dia.status) {
+        case (.high, .high), (.high, .normal), (.normal, .high): arrow = " ↑"
+        case (.low, .low), (.low, .normal), (.normal, .low):     arrow = " ↓"
+        default:                                                  arrow = ""
+        }
         return TimelineEntry(
             id: "bp-\(sys.persistentModelID)-\(dia.persistentModelID)",
             kind: .indicator,
             date: sys.capturedAt,
             title: String(appLoc: "血压"),
             subtitle: String(appLoc: "长期监测"),
-            trailing: "\(sys.value)/\(dia.value) mmHg" + (abnormal ? " ↑" : ""),
+            trailing: "\(sys.value)/\(dia.value) mmHg" + arrow,
             trailingIsAlert: abnormal,
             isOngoing: false
         )
     }
 
     static func from(report r: Report) -> TimelineEntry {
-        let abnormal = r.indicators.filter { $0.status != .normal }.count
+        let highCount = r.indicators.filter { $0.status == .high }.count
+        let lowCount  = r.indicators.filter { $0.status == .low }.count
         return TimelineEntry(
             id: "report-\(r.persistentModelID)",
             kind: .report,
             date: r.reportDate,
             title: r.title,
             subtitle: "\(r.type.label) · " + String(appLoc: "共 \(r.pageCount) 页"),
-            trailing: abnormal > 0 ? String(appLoc: "\(abnormal) 项偏高") : nil,
-            trailingIsAlert: abnormal > 0,
+            trailing: abnormalSummary(high: highCount, low: lowCount),
+            trailingIsAlert: highCount + lowCount > 0,
             isOngoing: false
         )
     }
 
+    /// 异常计数 → trailing 文案。只高→「N 项偏高」、只低→「N 项偏低」、混合→「N 项异常」、无→nil。
+    /// 旧实现一律写「N 项偏高」,只含偏低指标的报告会显示与事实相反的结论(demo 翻车点)。
+    static func abnormalSummary(high: Int, low: Int) -> String? {
+        switch (high, low) {
+        case (0, 0):         return nil
+        case (let h, 0):     return String(appLoc: "\(h) 项偏高")
+        case (0, let l):     return String(appLoc: "\(l) 项偏低")
+        case (let h, let l): return String(appLoc: "\(h + l) 项异常")
+        }
+    }
+
     static func from(diary d: DiaryEntry) -> TimelineEntry {
         TimelineEntry(
             id: "diary-\(d.persistentModelID)",