feat: 完成布局优化 - 操作列固定、批量按钮自适应、分类标签带数量

优化内容:
1. 表格布局:
   - 使用 calc(100vw - 160px) 确保表格不超出视口
   - 操作列 fixed='right' 固定在右侧，宽度 300px
   - 按钮 3 个后自动换行 (max-width: 200px)
   - 恢复合理列宽，不再过度压缩

2. 批量操作区域:
   - 容器改为 inline-block，宽度自适应按钮内容
   - 背景宽度与按钮总宽度匹配

3. 分类标签:
   - 显示数量 (如 '待处理 (20)')
   - 点击切换筛选，去掉误导的 'X' 图标

4. 删除功能:
   - 操作列增加删除按钮
   - 删除前弹出确认对话框

5. 系统日志:
   - 修复后端日志路径 (parents[4])
   - 404 时显示友好提示

6. 其他:
   - 左侧菜单宽度 160px
   - 所有功能保留 (登录、用户管理、批量操作等)

platform/backend/api/topics.py

@@ -0,0 +1,188 @@
+# 宇之然内容创作平台 - 选题管理API
+
+from datetime import datetime
+from fastapi import APIRouter, Depends, HTTPException, status, Query
+from sqlalchemy.orm import Session
+from typing import List, Optional
+import json
+
+from ..core.security import get_current_admin_user, create_audit_log
+from ..database import get_db
+from ..models import Topic, User
+
+router = APIRouter()
+
+class TopicCreateRequest(BaseModel):
+    title: str
+    field: Optional[str] = None
+    priority_score: int = 0
+
+class TopicUpdateRequest(BaseModel):
+    title: Optional[str] = None
+    field: Optional[str] = None
+    priority_score: Optional[int] = None
+    status: Optional[str] = None
+
+@router.get("/", response_model=List[dict])
+async def get_topics(
+    status: Optional[str] = Query(None),
+    page: int = Query(1, ge=1),
+    size: int = Query(20, ge=1, le=100),
+    db: Session = Depends(get_db)
+):
+    """获取选题列表"""
+    query = db.query(Topic)
+    
+    # 状态筛选
+    if status:
+        query = query.filter(Topic.status == status)
+    
+    # 分页
+    offset = (page - 1) * size
+    topics = query.offset(offset).limit(size).all()
+    
+    # 转换为字典格式
+    result = []
+    for topic in topics:
+        result.append({
+            "id": topic.id,
+            "title": topic.title,
+            "field": topic.field,
+            "priority_score": topic.priority_score,
+            "status": topic.status,
+            "compliance_score": topic.compliance_score,
+            "created_at": topic.created_at.isoformat() if topic.created_at else None,
+            "updated_at": topic.updated_at.isoformat() if topic.updated_at else None,
+            "generated_at": topic.generated_at.isoformat() if topic.generated_at else None,
+            "published_at": topic.published_at.isoformat() if topic.published_at else None,
+            "published_urls": topic.published_urls
+        })
+    
+    return result
+
+@router.post("/", response_model=dict)
+async def create_topic(
+    topic_data: TopicCreateRequest,
+    current_user: User = Depends(get_current_admin_user),
+    db: Session = Depends(get_db)
+):
+    """创建新选题（管理员功能）"""
+    new_topic = Topic(
+        title=topic_data.title,
+        field=topic_data.field,
+        priority_score=topic_data.priority_score,
+        status="待处理"
+    )
+    db.add(new_topic)
+    db.commit()
+    db.refresh(new_topic)
+    
+    # 记录审计日志
+    create_audit_log(
+        db=db,
+        user_id=current_user.id,
+        action="create_topic",
+        resource_type="topic",
+        resource_id=new_topic.id,
+        details=f"标题: {topic_data.title}"
+    )
+    
+    return {
+        "id": new_topic.id,
+        "title": new_topic.title,
+        "status": new_topic.status,
+        "created_at": new_topic.created_at.isoformat() if new_topic.created_at else None
+    }
+
+@router.put("/{topic_id}", response_model=dict)
+async def update_topic(
+    topic_id: int,
+    topic_data: TopicUpdateRequest,
+    current_user: User = Depends(get_current_admin_user),
+    db: Session = Depends(get_db)
+):
+    """更新选题信息（管理员功能）"""
+    topic = db.query(Topic).filter(Topic.id == topic_id).first()
+    if not topic:
+        raise HTTPException(status_code=404, detail="选题不存在")
+    
+    # 更新字段
+    if topic_data.title is not None:
+        topic.title = topic_data.title
+    if topic_data.field is not None:
+        topic.field = topic_data.field
+    if topic_data.priority_score is not None:
+        topic.priority_score = topic_data.priority_score
+    if topic_data.status is not None:
+        topic.status = topic_data.status
+    
+    topic.updated_at = datetime.utcnow()
+    db.commit()
+    db.refresh(topic)
+    
+    # 记录审计日志
+    create_audit_log(
+        db=db,
+        user_id=current_user.id,
+        action="update_topic",
+        resource_type="topic",
+        resource_id=topic_id,
+        details=f"状态更新为: {topic_data.status}"
+    )
+    
+    return {
+        "id": topic.id,
+        "title": topic.title,
+        "status": topic.status,
+        "updated_at": topic.updated_at.isoformat() if topic.updated_at else None
+    }
+
+@router.delete("/{topic_id}")
+async def delete_topic(
+    topic_id: int,
+    current_user: User = Depends(get_current_admin_user),
+    db: Session = Depends(get_db)
+):
+    """删除选题（管理员功能）"""
+    topic = db.query(Topic).filter(Topic.id == topic_id).first()
+    if not topic:
+        raise HTTPException(status_code=404, detail="选题不存在")
+    
+    db.delete(topic)
+    db.commit()
+    
+    # 记录审计日志
+    create_audit_log(
+        db=db,
+        user_id=current_user.id,
+        action="delete_topic",
+        resource_type="topic",
+        resource_id=topic_id,
+        details="选题已删除"
+    )
+    
+    return {"message": "选题已成功删除"}
+
+@router.get("/{topic_id}", response_model=dict)
+async def get_topic(
+    topic_id: int,
+    db: Session = Depends(get_db)
+):
+    """获取单个选题详情"""
+    topic = db.query(Topic).filter(Topic.id == topic_id).first()
+    if not topic:
+        raise HTTPException(status_code=404, detail="选题不存在")
+    
+    return {
+        "id": topic.id,
+        "title": topic.title,
+        "field": topic.field,
+        "priority_score": topic.priority_score,
+        "status": topic.status,
+        "compliance_score": topic.compliance_score,
+        "created_at": topic.created_at.isoformat() if topic.created_at else None,
+        "updated_at": topic.updated_at.isoformat() if topic.updated_at else None,
+        "generated_at": topic.generated_at.isoformat() if topic.generated_at else None,
+        "published_at": topic.published_at.isoformat() if topic.published_at else None,
+        "published_urls": topic.published_urls
+    }