智教助手平台：完整初始化

- 前端：Vue3 + TS + Element Plus，24 个页面路由（课件/组题/教案/动画/思维导图/作文批改/命题/课堂/资源/社区等）
- 后端：FastAPI + SQLAlchemy + SQLite，17 个路由模块，AI 服务层含降级模板
- AI：glm-5.x 推理模型已禁用思维链，确保输出真实内容
- 修复：ai_service 两处请求体注入 enable_thinking/thinking disabled
- 测试账号：13900999999 / test1234

backend/services/audit.py

@@ -0,0 +1,96 @@
+"""安全审计日志服务。
+
+提供 log_action() 用于在任意路由中记录安全相关事件。日志写入数据库 audit_logs 表，
+同时输出到 logger，便于后续接入文件/集中式日志收集。
+"""
+from __future__ import annotations
+
+import logging
+from typing import Any, Optional
+
+from fastapi import Request
+from sqlalchemy.orm import Session
+
+from models.audit import AuditLog
+from models.user import User
+
+logger = logging.getLogger(__name__)
+
+
+def _user_label(user: Optional[User]) -> str:
+    """返回用户可读标识：优先 username，其次 phone，最后 id。"""
+    if user is None:
+        return ""
+    for attr in ("username", "phone", "name"):
+        val = getattr(user, attr, None)
+        if val:
+            return str(val)
+    return str(getattr(user, "id", ""))
+
+
+def _client_ip(request: Optional[Request]) -> str:
+    if request is None:
+        return ""
+    try:
+        fwd = request.headers.get("x-forwarded-for")
+        if fwd:
+            return fwd.split(",")[0].strip()[:64]
+        client = getattr(request, "client", None)
+        if client and client.host:
+            return client.host[:64]
+    except Exception:
+        pass
+    return ""
+
+
+def _user_agent(request: Optional[Request]) -> str:
+    if request is None:
+        return ""
+    try:
+        return (request.headers.get("user-agent") or "")[:255]
+    except Exception:
+        return ""
+
+
+def log_action(
+    db: Session,
+    *,
+    action: str,
+    user: Optional[User] = None,
+    request: Optional[Request] = None,
+    target_type: str = "",
+    target_id: Any = "",
+    detail: str = "",
+    status: str = "success",
+) -> None:
+    """记录一条审计日志。失败不影响主流程。"""
+    try:
+        log = AuditLog(
+            user_id=user.id if user else None,
+            username=_user_label(user),
+            action=action[:64],
+            target_type=target_type[:32] if target_type else "",
+            target_id=str(target_id)[:64] if target_id else "",
+            detail=detail[:2000] if detail else "",
+            ip=_client_ip(request),
+            user_agent=_user_agent(request),
+            status=status[:16] if status else "success",
+        )
+        db.add(log)
+        db.commit()
+    except Exception as exc:  # pragma: no cover - 日志失败不应中断业务
+        logger.warning("audit log failed: %s", exc)
+        try:
+            db.rollback()
+        except Exception:
+            pass
+    # 同时输出到日志通道
+    logger.info(
+        "audit action=%s user=%s target=%s/%s status=%s ip=%s",
+        action,
+        _user_label(user),
+        target_type,
+        target_id,
+        status,
+        _client_ip(request),
+    )