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/adapters/kiro/context.py

@@ -0,0 +1,82 @@
+from __future__ import annotations
+
+import contextvars
+from dataclasses import dataclass, replace
+
+
+@dataclass(frozen=True, slots=True)
+class KiroRequestContext:
+    """Per-request context for the Kiro adapter.
+
+    This bridges data from `KiroEnvelope.wrap_request()` (which receives the
+    decrypted auth_config + original request body) to other layers that only
+    expose parameterless hooks (extra_headers) or transport hooks.
+    """
+
+    region: str
+    machine_id: str
+    kiro_version: str | None = None
+    system_version: str | None = None
+    node_version: str | None = None
+    thinking_enabled: bool = False
+    last_http_status: int | None = None
+    last_http_error_category: str | None = None
+    last_connection_error_category: str | None = None
+    last_connection_error_summary: str | None = None
+
+
+_kiro_request_context: contextvars.ContextVar[KiroRequestContext | None] = contextvars.ContextVar(
+    "kiro_request_context",
+    default=None,
+)
+
+
+def set_kiro_request_context(ctx: KiroRequestContext | None) -> None:
+    _kiro_request_context.set(ctx)
+
+
+def get_kiro_request_context() -> KiroRequestContext | None:
+    return _kiro_request_context.get()
+
+
+def update_kiro_http_status(
+    *,
+    status_code: int,
+    category: str,
+) -> None:
+    ctx = get_kiro_request_context()
+    if ctx is None:
+        return
+    set_kiro_request_context(
+        replace(
+            ctx,
+            last_http_status=int(status_code),
+            last_http_error_category=str(category),
+        )
+    )
+
+
+def update_kiro_connection_error(
+    *,
+    category: str,
+    summary: str,
+) -> None:
+    ctx = get_kiro_request_context()
+    if ctx is None:
+        return
+    set_kiro_request_context(
+        replace(
+            ctx,
+            last_connection_error_category=str(category),
+            last_connection_error_summary=str(summary),
+        )
+    )
+
+
+__all__ = [
+    "KiroRequestContext",
+    "get_kiro_request_context",
+    "set_kiro_request_context",
+    "update_kiro_connection_error",
+    "update_kiro_http_status",
+]