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/api/admin/endpoints/concurrency.py

@@ -0,0 +1,99 @@
+"""
+Key RPM 限制管理 API
+"""
+
+from dataclasses import dataclass
+from typing import Any
+
+from fastapi import APIRouter, Depends, Request
+from sqlalchemy.orm import Session
+
+from src.api.base.admin_adapter import AdminApiAdapter
+from src.api.base.context import ApiRequestContext
+from src.api.base.pipeline import get_pipeline
+from src.core.exceptions import NotFoundException
+from src.database import get_db
+from src.models.database import ProviderAPIKey
+from src.models.endpoint_models import KeyRpmStatusResponse
+from src.services.rate_limit.concurrency_manager import get_concurrency_manager
+
+router = APIRouter(tags=["RPM Control"])
+pipeline = get_pipeline()
+
+
+@router.get("/rpm/key/{key_id}", response_model=KeyRpmStatusResponse)
+async def get_key_rpm(
+    key_id: str,
+    request: Request,
+    db: Session = Depends(get_db),
+) -> KeyRpmStatusResponse:
+    """
+    获取 Key 当前 RPM 状态
+
+    查询指定 API Key 的实时 RPM 使用情况，包括当前 RPM 计数和最大 RPM 限制。
+
+    **路径参数**:
+    - `key_id`: API Key ID
+
+    **返回字段**:
+    - `key_id`: API Key ID
+    - `current_rpm`: 当前 RPM 计数
+    - `rpm_limit`: RPM 限制
+    """
+    adapter = AdminKeyRpmAdapter(key_id=key_id)
+    return await pipeline.run(adapter=adapter, http_request=request, db=db, mode=adapter.mode)
+
+
+@router.delete("/rpm/key/{key_id}")
+async def reset_key_rpm(
+    key_id: str,
+    http_request: Request,
+    db: Session = Depends(get_db),
+) -> dict:
+    """
+    重置 Key RPM 计数器
+
+    重置指定 API Key 的 RPM 计数器，用于解决计数不准确的问题。
+    管理员功能，请谨慎使用。
+
+    **路径参数**:
+    - `key_id`: API Key ID
+
+    **返回字段**:
+    - `message`: 操作结果消息
+    """
+    adapter = AdminResetKeyRpmAdapter(key_id=key_id)
+    return await pipeline.run(adapter=adapter, http_request=http_request, db=db, mode=adapter.mode)
+
+
+# -------- Adapters --------
+
+
+@dataclass
+class AdminKeyRpmAdapter(AdminApiAdapter):
+    key_id: str
+
+    async def handle(self, context: ApiRequestContext) -> Any:  # type: ignore[override]
+        db = context.db
+        key = db.query(ProviderAPIKey).filter(ProviderAPIKey.id == self.key_id).first()
+        if not key:
+            raise NotFoundException(f"Key {self.key_id} 不存在")
+
+        concurrency_manager = await get_concurrency_manager()
+        key_count = await concurrency_manager.get_key_rpm_count(key_id=self.key_id)
+
+        return KeyRpmStatusResponse(
+            key_id=self.key_id,
+            current_rpm=key_count,
+            rpm_limit=key.rpm_limit,
+        )
+
+
+@dataclass
+class AdminResetKeyRpmAdapter(AdminApiAdapter):
+    key_id: str
+
+    async def handle(self, context: ApiRequestContext) -> Any:  # type: ignore[override]
+        concurrency_manager = await get_concurrency_manager()
+        await concurrency_manager.reset_key_rpm(key_id=self.key_id)
+        return {"message": "RPM 计数已重置"}