fix: sessionsCount 修复 + 手动会话结束更新 DailyLearningActivity

- upsertFromReadingEvent 加 isNewSession 参数，material_opened 时 increment sessionsCount
- LearningSessionService.end() 调用 incrementDailySessions 更新日活会话计数

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

src/modules/learning-activity/learning-activity.repository.ts

@@ -27,9 +27,10 @@ export class LearningActivityRepository {
     activeSecondsDelta: number;
     isNewMaterial?: boolean;
     isMarkedRead?: boolean;
+    isNewSession?: boolean;
   }) {
     const activityDate = this.computeActivityDate(data.clientTimestampMs, data.clientTimezoneOffsetMinutes);
-    const { userId, activeSecondsDelta, isNewMaterial, isMarkedRead } = data;
+    const { userId, activeSecondsDelta, isNewMaterial, isMarkedRead, isNewSession } = data;
 
     return tx.dailyLearningActivity.upsert({
       where: { userId_activityDate: { userId, activityDate } },
@@ -40,16 +41,28 @@ export class LearningActivityRepository {
         readingSeconds: activeSecondsDelta,
         materialsReadCount: isNewMaterial ? 1 : 0,
         markedReadCount: isMarkedRead ? 1 : 0,
+        sessionsCount: isNewSession ? 1 : 0,
       },
       update: {
         durationSeconds: { increment: activeSecondsDelta },
         readingSeconds: { increment: activeSecondsDelta },
         materialsReadCount: isNewMaterial ? { increment: 1 } : undefined,
         markedReadCount: isMarkedRead ? { increment: 1 } : undefined,
+        sessionsCount: isNewSession ? { increment: 1 } : undefined,
       },
     });
   }
 
+  /** Increment sessionsCount for a given day (called from manual session end). */
+  async incrementDailySessions(userId: string, activityDate: Date) {
+    const date = new Date(Date.UTC(activityDate.getUTCFullYear(), activityDate.getUTCMonth(), activityDate.getUTCDate()));
+    return this.prisma.dailyLearningActivity.upsert({
+      where: { userId_activityDate: { userId, activityDate: date } },
+      create: { userId, activityDate: date, sessionsCount: 1 },
+      update: { sessionsCount: { increment: 1 } },
+    }).catch(() => {});
+  }
+
   /** Compute local date from timestamp and timezone offset. */
   private computeActivityDate(timestampMs: bigint, offsetMinutes: number | null): Date {
     const offsetMs = (offsetMinutes ?? 0) * 60 * 1000;

src/modules/learning-session/learning-session.service.ts

@@ -1,9 +1,13 @@
 import { Injectable, NotFoundException } from '@nestjs/common';
 import { LearningSessionRepository } from './learning-session.repository';
+import { LearningActivityRepository } from '../learning-activity/learning-activity.repository';
 
 @Injectable()
 export class LearningSessionService {
-  constructor(private readonly repository: LearningSessionRepository) {}
+  constructor(
+    private readonly repository: LearningSessionRepository,
+    private readonly activityRepo: LearningActivityRepository,
+  ) {}
 
   async start(userId: string, dto: any) {
     return this.repository.create(userId, dto);
@@ -12,6 +16,10 @@ export class LearningSessionService {
   async end(id: string) {
     const session = await this.repository.end(id);
     if (!session) throw new NotFoundException('会话不存在');
+    // 更新 DailyLearningActivity 的会话计数
+    if (session.userId) {
+      this.activityRepo.incrementDailySessions(session.userId, session.startedAt ?? new Date());
+    }
     return session;
   }
 

src/modules/reading-event/reading-event-processor.service.ts

@@ -148,6 +148,7 @@ export class ReadingEventProcessorService {
         activeSecondsDelta: validated.activeSecondsDelta,
         isNewMaterial: validated.eventType === 'material_opened',
         isMarkedRead: validated.eventType === 'marked_as_read',
+        isNewSession: validated.eventType === 'material_opened',
       });
 
       // 5d. Write LearningRecord (first open / closed / marked read)