feat: 运营报告生成功能

- 后端新增 /admin/stats/report 接口，生成14天运营数据报告
- 报告内容：垃圾信息变化趋势、高频风险词Top10、误判率趋势
- 前端运营看板增加"生成报告"按钮，展示完整报告
- 支持复制报告文本到剪贴板

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

backend/app/routes/admin_routes.py

@@ -147,6 +147,114 @@ def stats():
     )
 
 
+@admin_bp.get("/stats/report")
+@admin_required
+def generate_report():
+    """生成运营报告：垃圾信息变化、风险词排名、误判率趋势"""
+    now = datetime.utcnow()
+    week_ago = now - timedelta(days=13)  # 近14天
+
+    # 1. 垃圾信息数量变化（近14天）
+    blocked_trend_rows = (
+        db.session.query(func.date(ContentPost.created_at), func.count(ContentPost.id))
+        .filter(ContentPost.created_at >= week_ago, ContentPost.status == "blocked")
+        .group_by(func.date(ContentPost.created_at))
+        .all()
+    )
+    published_trend_rows = (
+        db.session.query(func.date(ContentPost.created_at), func.count(ContentPost.id))
+        .filter(ContentPost.created_at >= week_ago, ContentPost.status == "published")
+        .group_by(func.date(ContentPost.created_at))
+        .all()
+    )
+
+    blocked_map = {_day_key(day): int(count or 0) for day, count in blocked_trend_rows}
+    published_map = {_day_key(day): int(count or 0) for day, count in published_trend_rows}
+
+    spam_trend = []
+    today = now.date()
+    for offset in range(13, -1, -1):
+        day = today - timedelta(days=offset)
+        key = day.isoformat()
+        spam_trend.append({
+            "date": key,
+            "label": day.strftime("%m-%d"),
+            "blocked": blocked_map.get(key, 0),
+            "published": published_map.get(key, 0),
+            "total": blocked_map.get(key, 0) + published_map.get(key, 0)
+        })
+
+    # 2. 高频风险词排名（近14天）
+    blocked_logs = (
+        ContentPost.query.filter(ContentPost.created_at >= week_ago, ContentPost.status == "blocked")
+        .order_by(ContentPost.id.desc())
+        .limit(1000)
+        .all()
+    )
+    token_counter = Counter()
+    for row in blocked_logs:
+        token_counter.update(_tokenize(row.text))
+    top_keywords = [{"token": token, "count": count} for token, count in token_counter.most_common(20)]
+
+    # 3. 误判率趋势（近14天，基于人工复核）
+    review_trend_rows = (
+        db.session.query(func.date(ContentPost.manual_review_at), func.count(ContentPost.id))
+        .filter(ContentPost.manual_review_at >= week_ago, ContentPost.manual_review_status != "none")
+        .group_by(func.date(ContentPost.manual_review_at))
+        .all()
+    )
+    approved_trend_rows = (
+        db.session.query(func.date(ContentPost.manual_review_at), func.count(ContentPost.id))
+        .filter(ContentPost.manual_review_at >= week_ago, ContentPost.manual_review_status == "approved_ham")
+        .group_by(func.date(ContentPost.manual_review_at))
+        .all()
+    )
+
+    review_map = {_day_key(day): int(count or 0) for day, count in review_trend_rows}
+    approved_map = {_day_key(day): int(count or 0) for day, count in approved_trend_rows}
+
+    misjudge_trend = []
+    for offset in range(13, -1, -1):
+        day = today - timedelta(days=offset)
+        key = day.isoformat()
+        reviewed = review_map.get(key, 0)
+        approved = approved_map.get(key, 0)
+        misjudge_rate = round(approved / reviewed, 4) if reviewed > 0 else 0
+        misjudge_trend.append({
+            "date": key,
+            "label": day.strftime("%m-%d"),
+            "reviewed": reviewed,
+            "approved": approved,
+            "misjudge_rate": misjudge_rate,
+            "misjudge_rate_text": f"{misjudge_rate * 100:.1f}%"
+        })
+
+    # 4. 汇总统计
+    total_blocked_14d = sum(blocked_map.values())
+    total_published_14d = sum(published_map.values())
+    total_reviews_14d = sum(review_map.values())
+    total_approved_14d = sum(approved_map.values())
+    avg_misjudge_rate = round(total_approved_14d / total_reviews_14d, 4) if total_reviews_14d > 0 else 0
+
+    return ok({
+        "report_date": now.isoformat(),
+        "period": "近14天",
+        "spam_trend": spam_trend,
+        "top_keywords": top_keywords,
+        "misjudge_trend": misjudge_trend,
+        "summary": {
+            "total_blocked": total_blocked_14d,
+            "total_published": total_published_14d,
+            "total_posts": total_blocked_14d + total_published_14d,
+            "blocked_ratio": round(total_blocked_14d / (total_blocked_14d + total_published_14d), 4) if (total_blocked_14d + total_published_14d) > 0 else 0,
+            "total_reviews": total_reviews_14d,
+            "total_approved": total_approved_14d,
+            "avg_misjudge_rate": avg_misjudge_rate,
+            "avg_misjudge_rate_text": f"{avg_misjudge_rate * 100:.1f}%"
+        }
+    })
+
+
 @admin_bp.get("/detection/threshold")
 @admin_required
 def get_threshold():