feat: 增加案例/任务日志/LLM配置/系统配置管理功能\n\n- 扩展案例数据至30个\n- 新增Case, TaskLog, LLMConfig, SystemConfig的API路由\n- 完善initial_data导入脚本\n- 创建前端管理页面admin.html，支持完整增删改查\n- 更新导航菜单，增加系统管理入口

platform/backend/app/api/cases.py

@@ -0,0 +1,95 @@
+from fastapi import APIRouter, Depends, HTTPException, Request
+from sqlalchemy.orm import Session
+from typing import List
+
+from ..database import get_db
+from ..models import Case
+from ..schemas import CaseBase, CaseResponse
+
+router = APIRouter(prefix="/api/admin/cases", tags=["admin"])
+
+def get_current_admin(request: Request, db: Session = Depends(get_db)):
+    """依赖项：验证管理员权限"""
+    from .auth import verify_token
+    auth_header = request.headers.get("Authorization")
+    if not auth_header or not auth_header.startswith("Bearer "):
+        raise HTTPException(status_code=401, detail="未提供认证令牌")
+    token = auth_header.split(" ")[1]
+    user = verify_token(token, db)
+    if user.role != "admin":
+        raise HTTPException(status_code=403, detail="需要管理员权限")
+    return user
+
+@router.get("", response_model=List[CaseResponse])
+def list_cases(
+    request: Request,
+    db: Session = Depends(get_db),
+    admin_user = Depends(get_current_admin)
+):
+    """获取案例列表（管理员）"""
+    cases = db.query(Case).all()
+    return [CaseResponse.from_orm(c) for c in cases]
+
+@router.get("/{case_id}", response_model=CaseResponse)
+def get_case(
+    case_id: int,
+    request: Request,
+    db: Session = Depends(get_db),
+    admin_user = Depends(get_current_admin)
+):
+    """获取单个案例详情"""
+    case = db.query(Case).filter(Case.id == case_id).first()
+    if not case:
+        raise HTTPException(status_code=404, detail="案例不存在")
+    return case
+
+@router.post("", response_model=CaseResponse)
+def create_case(
+    case_data: CaseBase,
+    request: Request,
+    db: Session = Depends(get_db),
+    admin_user = Depends(get_current_admin)
+):
+    """创建新案例"""
+    existing = db.query(Case).filter(Case.id == case_data.id).first()
+    if existing:
+        raise HTTPException(status_code=400, detail="案例ID已存在")
+    case = Case(**case_data.dict())
+    db.add(case)
+    db.commit()
+    db.refresh(case)
+    return case
+
+@router.put("/{case_id}", response_model=CaseResponse)
+def update_case(
+    case_id: int,
+    case_update: CaseBase,
+    request: Request,
+    db: Session = Depends(get_db),
+    admin_user = Depends(get_current_admin)
+):
+    """更新案例"""
+    case = db.query(Case).filter(Case.id == case_id).first()
+    if not case:
+        raise HTTPException(status_code=404, detail="案例不存在")
+    update_data = case_update.dict(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(case, field, value)
+    db.commit()
+    db.refresh(case)
+    return case
+
+@router.delete("/{case_id}")
+def delete_case(
+    case_id: int,
+    request: Request,
+    db: Session = Depends(get_db),
+    admin_user = Depends(get_current_admin)
+):
+    """删除案例"""
+    case = db.query(Case).filter(Case.id == case_id).first()
+    if not case:
+        raise HTTPException(status_code=404, detail="案例不存在")
+    db.delete(case)
+    db.commit()
+    return {"message": "删除成功"}