feat: 核心模块增强 — 加密 + 运行时配置 + 日志缓冲

- crypto.py: API Key 加密/解密工具
- runtime_config.py: 运行时动态配置管理
- log_buffer.py: 内存日志缓冲区
- config.py: 新增加密配置项
- http_client.py: 增强重试和错误处理

src/core/log_buffer.py

@@ -0,0 +1,82 @@
+"""内存日志缓冲:供后台「系统日志」页查看应用运行日志。
+
+把应用日志(stdout)同时捕获到进程内环形缓冲(deque),提供级别/关键字/条数
+过滤查询。缓冲在进程重启后清零;需要持久化的审计请另行落库。
+"""
+from __future__ import annotations
+
+import logging
+import threading
+from collections import deque
+
+_BUFFER: deque[dict] = deque(maxlen=2000)
+_LOCK = threading.Lock()
+
+_LEVEL_ORDER = {"DEBUG": 10, "INFO": 20, "WARNING": 30, "ERROR": 40, "CRITICAL": 50}
+
+
+class MemoryLogHandler(logging.Handler):
+    """把日志记录写入内存环形缓冲。"""
+
+    def __init__(self) -> None:
+        super().__init__()
+        # format() 会在有 exc_info 时自动附带异常堆栈文本
+        self.setFormatter(logging.Formatter("%(message)s"))
+
+    def emit(self, record: logging.LogRecord) -> None:
+        try:
+            entry = {
+                "ts": record.created,
+                "level": record.levelname,
+                "logger": record.name,
+                "message": self.format(record),
+            }
+            with _LOCK:
+                _BUFFER.append(entry)
+        except Exception:  # noqa: BLE001  日志采集绝不影响业务
+            self.handleError(record)
+
+
+class _SQLNoiseFilter(logging.Filter):
+    """过滤 SQLAlchemy 的 DEBUG/INFO 回显(只留警告以上)。"""
+
+    def filter(self, record: logging.LogRecord) -> bool:
+        return not (
+            record.name.startswith("sqlalchemy.") and record.levelno < logging.WARNING
+        )
+
+
+def get_entries(
+    min_level: str | None = None,
+    keyword: str | None = None,
+    limit: int = 200,
+) -> list[dict]:
+    """按条件查询缓冲日志,最新在前。"""
+    min_no = _LEVEL_ORDER.get((min_level or "").upper(), 0)
+    kw = (keyword or "").strip().lower()
+    with _LOCK:
+        items = list(_BUFFER)
+    items.reverse()
+    out: list[dict] = []
+    for e in items:
+        if _LEVEL_ORDER.get(e["level"], 0) < min_no:
+            continue
+        if kw and kw not in e["message"].lower() and kw not in e["logger"].lower():
+            continue
+        out.append(e)
+        if len(out) >= limit:
+            break
+    return out
+
+
+def setup_memory_logging(level: str = "INFO") -> None:
+    """挂载内存 handler 到 root logger(幂等),并确保 root 级别不低于 INFO。"""
+    root = logging.getLogger()
+    if any(isinstance(h, MemoryLogHandler) for h in root.handlers):
+        return
+    handler = MemoryLogHandler()
+    handler.setLevel(logging.INFO)
+    handler.addFilter(_SQLNoiseFilter())
+    root.addHandler(handler)
+    if root.level == logging.NOTSET or root.level > logging.INFO:
+        root.setLevel(getattr(logging, level.upper(), logging.INFO))