feat: 新增工具插件、系统日志、workflow配置及前端优化

1. 新增工具插件(edit_file, python_executor, search_file, shell_executor, write_file)
2. 新增系统事件日志模块和API
3. 新增workflow配置文件和详情API
4. 前端增加SSE、错误边界、设置引导等组件
5. 优化认证加密、速率限制、配置加载等工具模块
6. 删除废弃的cluster和health API
7. 补充单元测试和集成测试

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

kilostar/utils/rate_limit.py

@@ -0,0 +1,45 @@
+import time
+from collections import defaultdict
+from typing import Dict, Tuple
+
+from fastapi import HTTPException, Request
+
+
+class InMemoryRateLimiter:
+    """基于滑动窗口的内存限流器。
+
+    按 IP 地址追踪请求次数，超出阈值时抛出 429。
+    适用于单实例部署；集群部署应替换为 Redis 后端。
+    """
+
+    def __init__(self, max_requests: int = 5, window_seconds: int = 60):
+        self._max_requests = max_requests
+        self._window_seconds = window_seconds
+        self._requests: Dict[str, list[float]] = defaultdict(list)
+
+    def _get_client_ip(self, request: Request) -> str:
+        forwarded = request.headers.get("X-Forwarded-For")
+        if forwarded:
+            return forwarded.split(",")[0].strip()
+        return request.client.host if request.client else "unknown"
+
+    def _cleanup(self, key: str, now: float) -> None:
+        cutoff = now - self._window_seconds
+        self._requests[key] = [
+            t for t in self._requests[key] if t > cutoff
+        ]
+
+    def check(self, request: Request) -> None:
+        now = time.time()
+        key = self._get_client_ip(request)
+        self._cleanup(key, now)
+        if len(self._requests[key]) >= self._max_requests:
+            raise HTTPException(
+                status_code=429,
+                detail="请求过于频繁，请稍后再试",
+            )
+        self._requests[key].append(now)
+
+
+register_limiter = InMemoryRateLimiter(max_requests=5, window_seconds=60)
+login_limiter = InMemoryRateLimiter(max_requests=10, window_seconds=60)