refactor: 移除 Python 后端源码，全面迁移至 Rust gateway 架构

- 删除全部 Python 源码 (src/) 及 Alembic 迁移脚本，归档至 _deprecated_py_src/
- 重构 Rust gateway ai_pipeline: 拆分 planner/finalize 模块，新增 contracts/adaptation 层
- 重组 handlers 模块为 admin/public/proxy/internal/shared 子模块结构
- 新增 executor 模块，引入 Rust 原生数据库迁移 (aether-data/migrations)
- 简化 CI/Docker 构建流程，移除 base image 二级构建，统一为单一 app image
- 移除 Python 相关基础设施文件 (entrypoint.sh, gunicorn_conf.py, Dockerfile.base)

_deprecated_py_src/plugins/monitor/base.py

@@ -0,0 +1,250 @@
+"""
+监控插件基类
+定义监控和指标收集的接口
+"""
+
+from __future__ import annotations
+
+from abc import abstractmethod
+from datetime import datetime, timezone
+from enum import Enum
+from typing import Any
+
+from src.plugins.common import BasePlugin
+
+
+class MetricType(Enum):
+    """指标类型"""
+
+    COUNTER = "counter"  # 计数器（只增不减）
+    GAUGE = "gauge"  # 仪表（可增可减）
+    HISTOGRAM = "histogram"  # 直方图（分布）
+    SUMMARY = "summary"  # 摘要（分位数）
+
+
+class Metric:
+    """指标数据"""
+
+    def __init__(
+        self,
+        name: str,
+        value: float,
+        metric_type: MetricType,
+        labels: dict[str, str] | None = None,
+        timestamp: datetime | None = None,
+        description: str | None = None,
+    ):
+        self.name = name
+        self.value = value
+        self.metric_type = metric_type
+        self.labels = labels or {}
+        self.timestamp = timestamp or datetime.now(timezone.utc)
+        self.description = description
+
+
+class MonitorPlugin(BasePlugin):
+    """
+    监控插件基类
+    所有监控插件必须继承此类并实现相关方法
+    """
+
+    def __init__(self, name: str, config: dict[str, Any] | None = None):
+        """
+        初始化监控插件
+
+        Args:
+            name: 插件名称
+            config: 配置字典
+        """
+        # 调用父类初始化，设置metadata
+        super().__init__(name=name, config=config, description="Monitor Plugin", version="1.0.0")
+
+        self.flush_interval = self.config.get("flush_interval", 60)
+        self.batch_size = self.config.get("batch_size", 100)
+
+    @abstractmethod
+    async def record_metric(self, metric: Metric) -> None:
+        """
+        记录单个指标
+
+        Args:
+            metric: 指标数据
+        """
+        pass
+
+    @abstractmethod
+    async def record_batch(self, metrics: list[Metric]) -> None:
+        """
+        批量记录指标
+
+        Args:
+            metrics: 指标列表
+        """
+        pass
+
+    @abstractmethod
+    async def increment(
+        self, name: str, value: float = 1, labels: dict[str, str] | None = None
+    ) -> Any:
+        """
+        增加计数器
+
+        Args:
+            name: 指标名称
+            value: 增加的值
+            labels: 标签字典
+        """
+        pass
+
+    @abstractmethod
+    async def gauge(self, name: str, value: float, labels: dict[str, str] | None = None) -> Any:
+        """
+        设置仪表值
+
+        Args:
+            name: 指标名称
+            value: 仪表值
+            labels: 标签字典
+        """
+        pass
+
+    @abstractmethod
+    async def histogram(
+        self,
+        name: str,
+        value: float,
+        labels: dict[str, str] | None = None,
+        buckets: list[float] | None = None,
+    ) -> Any:
+        """
+        记录直方图数据
+
+        Args:
+            name: 指标名称
+            value: 观测值
+            labels: 标签字典
+            buckets: 桶边界
+        """
+        pass
+
+    @abstractmethod
+    async def timing(self, name: str, duration: float, labels: dict[str, str] | None = None) -> Any:
+        """
+        记录时间指标
+
+        Args:
+            name: 指标名称
+            duration: 持续时间（秒）
+            labels: 标签字典
+        """
+        pass
+
+    @abstractmethod
+    async def flush(self) -> Any:
+        """
+        刷新缓冲的指标到后端
+        """
+        pass
+
+    @abstractmethod
+    async def get_stats(self) -> dict[str, Any]:
+        """
+        获取插件统计信息
+
+        Returns:
+            统计信息字典
+        """
+        pass
+
+    def record_request(
+        self,
+        method: str,
+        endpoint: str,
+        status_code: int,
+        duration: float,
+        provider: str | None = None,
+        model: str | None = None,
+    ) -> Any:
+        """
+        记录API请求指标（便捷方法）
+
+        Args:
+            method: HTTP方法
+            endpoint: 端点路径
+            status_code: 状态码
+            duration: 请求时长
+            provider: 提供商名称
+            model: 模型名称
+        """
+        labels = {
+            "method": method,
+            "endpoint": endpoint,
+            "status": str(status_code),
+            "status_class": f"{status_code // 100}xx",
+        }
+
+        if provider:
+            labels["provider"] = provider
+        if model:
+            labels["model"] = model
+
+        # 异步记录指标
+        from src.utils.async_utils import safe_create_task
+
+        # 请求计数
+        safe_create_task(self.increment("http_requests_total", labels=labels))
+
+        # 请求延迟
+        safe_create_task(self.histogram("http_request_duration_seconds", duration, labels=labels))
+
+        # 错误计数
+        if status_code >= 400:
+            safe_create_task(self.increment("http_errors_total", labels=labels))
+
+    def record_token_usage(
+        self,
+        provider: str,
+        model: str,  # noqa: ARG002 - 保留签名兼容性，不再用于 Prometheus 标签
+        input_tokens: int,
+        output_tokens: int,
+        cost: float | None = None,
+    ) -> Any:
+        """
+        记录Token使用指标（便捷方法）
+
+        Args:
+            provider: 提供商名称
+            model: 模型名称（保留签名兼容性，不再作为 Prometheus 标签）
+            input_tokens: 输入token数
+            output_tokens: 输出token数
+            cost: 费用
+        """
+        labels = {"provider": provider}
+
+        from src.utils.async_utils import safe_create_task
+
+        # Token计数
+        safe_create_task(self.increment("tokens_input_total", input_tokens, labels=labels))
+        safe_create_task(self.increment("tokens_output_total", output_tokens, labels=labels))
+        safe_create_task(
+            self.increment("tokens_total", input_tokens + output_tokens, labels=labels)
+        )
+
+        # 费用
+        if cost is not None:
+            safe_create_task(self.increment("usage_cost_total", cost, labels=labels))
+
+    def configure(self, config: dict[str, Any]) -> Any:
+        """
+        配置插件
+
+        Args:
+            config: 配置字典
+        """
+        self.config.update(config)
+        self.enabled = config.get("enabled", True)
+        self.flush_interval = config.get("flush_interval", self.flush_interval)
+        self.batch_size = config.get("batch_size", self.batch_size)
+
+    def __repr__(self) -> None:
+        return f"<{self.__class__.__name__}(name={self.name}, enabled={self.enabled})>"