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/services/provider_ops/registry.py

@@ -0,0 +1,149 @@
+"""
+架构注册表
+
+管理所有可用的 Provider 架构。
+"""
+
+from __future__ import annotations
+
+import threading
+
+from src.core.logger import logger
+from src.services.provider_ops.architectures import (
+    AnyrouterArchitecture,
+    CubenceArchitecture,
+    GenericApiArchitecture,
+    NekoCodeArchitecture,
+    NewApiArchitecture,
+    ProviderArchitecture,
+    Sub2ApiArchitecture,
+    YesCodeArchitecture,
+)
+
+
+class ArchitectureRegistry:
+    """
+    架构注册表
+
+    单例模式，管理所有可用的 Provider 架构。
+    """
+
+    _instance: ArchitectureRegistry | None = None
+    _lock = threading.Lock()
+    _initialized: bool = False
+
+    def __new__(cls) -> ArchitectureRegistry:
+        if cls._instance is None:
+            with cls._lock:
+                if cls._instance is None:
+                    cls._instance = super().__new__(cls)
+                    cls._instance._initialized = False
+        return cls._instance
+
+    def __init__(self) -> None:
+        if self._initialized:
+            return
+
+        self._architectures: dict[str, ProviderArchitecture] = {}
+        self._initialized = True
+
+        # 注册内置架构
+        self._register_builtin_architectures()
+
+    def _register_builtin_architectures(self) -> None:
+        """注册内置架构"""
+        builtin: list[type[ProviderArchitecture]] = [
+            AnyrouterArchitecture,
+            CubenceArchitecture,
+            GenericApiArchitecture,
+            NekoCodeArchitecture,
+            NewApiArchitecture,
+            Sub2ApiArchitecture,
+            YesCodeArchitecture,
+        ]
+
+        for arch_cls in builtin:
+            self.register(arch_cls(), _quiet=True)
+        logger.debug(f"内置架构注册完成: {', '.join(self._architectures.keys())}")
+
+    def register(self, architecture: ProviderArchitecture, *, _quiet: bool = False) -> None:
+        """
+        注册架构
+
+        Args:
+            architecture: 架构实例
+            _quiet: 内部参数，批量注册时抑制逐条日志
+        """
+        if architecture.architecture_id in self._architectures:
+            logger.warning(f"架构 {architecture.architecture_id} 已存在，将被覆盖")
+
+        self._architectures[architecture.architecture_id] = architecture
+        if not _quiet:
+            logger.debug(f"注册架构: {architecture.architecture_id}")
+
+    def unregister(self, architecture_id: str) -> bool:
+        """
+        注销架构
+
+        Args:
+            architecture_id: 架构 ID
+
+        Returns:
+            是否成功注销
+        """
+        if architecture_id in self._architectures:
+            del self._architectures[architecture_id]
+            return True
+        return False
+
+    def get(self, architecture_id: str) -> ProviderArchitecture | None:
+        """
+        获取架构
+
+        Args:
+            architecture_id: 架构 ID
+
+        Returns:
+            架构实例，不存在则返回 None
+        """
+        return self._architectures.get(architecture_id)
+
+    def get_or_default(self, architecture_id: str | None = None) -> ProviderArchitecture:
+        """
+        获取架构，如果不存在则返回默认架构
+
+        Args:
+            architecture_id: 架构 ID
+
+        Returns:
+            架构实例
+        """
+        if architecture_id and architecture_id in self._architectures:
+            return self._architectures[architecture_id]
+
+        # 返回默认架构（generic_api）
+        return self._architectures.get("generic_api", GenericApiArchitecture())
+
+    def list_all(self) -> list[ProviderArchitecture]:
+        """获取所有已注册的架构"""
+        return list(self._architectures.values())
+
+    def list_ids(self) -> list[str]:
+        """获取所有已注册的架构 ID"""
+        return list(self._architectures.keys())
+
+    def to_dict_list(self) -> list[dict]:
+        """获取所有架构的字典表示（用于 API 响应，隐藏 hidden 架构）"""
+        return [arch.to_dict() for arch in self._architectures.values() if not arch.hidden]
+
+
+# 全局注册表实例
+_registry: ArchitectureRegistry | None = None
+
+
+def get_registry() -> ArchitectureRegistry:
+    """获取全局注册表实例"""
+    global _registry
+    if _registry is None:
+        _registry = ArchitectureRegistry()
+    return _registry