feat: 引入 Rust executor/gateway sidecar 及 Python 侧双后端适配

- 新增 Rust workspace crates: aether-contracts, aether-executor, aether-gateway
- aether-executor: 支持 Unix Socket/TCP 双传输模式，处理同步/流式上游请求
- aether-gateway: 作为本地主入口代理，集成 /api/internal/gateway/resolve 认证预解析
- Python 侧新增 ExecutionPlan 契约和 RustExecutorClient，各 handler 支持
  executor_backend=rust 时将可序列化请求转发给 Rust executor 执行
- 重构 dev.sh 支持 executor/gateway 进程编排与生命周期管理
- 新增 internal gateway 路由，提供 resolve/passthrough 端点
- handler 层(chat/cli/video/endpoint_checker 等)全面适配 Rust executor 回退逻辑
- pipeline 层支持 trusted auth context 跳过重复认证
- 新增 Rust CI workflow 及对应测试用例

tests/api/handlers/base/test_endpoint_checker_rust.py

@@ -0,0 +1,168 @@
+from __future__ import annotations
+
+from typing import Any
+from unittest.mock import AsyncMock
+
+import pytest
+
+from src.api.handlers.base.endpoint_checker import EndpointCheckRequest, HttpRequestExecutor
+from src.services.request.rust_executor_client import (
+    RustExecutorStreamResult,
+    RustExecutorSyncResult,
+)
+
+
+class _DummyStreamContext:
+    def __init__(self) -> None:
+        self.closed = False
+
+    async def __aexit__(self, exc_type: object, exc: object, tb: object) -> None:
+        self.closed = True
+
+
+@pytest.mark.asyncio
+async def test_endpoint_checker_sync_prefers_rust_executor(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    from src.api.handlers.base import endpoint_checker as mod
+    from src.services.request import rust_executor_client as rust_mod
+
+    monkeypatch.setattr(mod.config, "executor_backend", "rust")
+
+    executor = HttpRequestExecutor(timeout=15.0)
+    proxy_snapshot = object()
+    monkeypatch.setattr(
+        executor,
+        "_build_rust_proxy_snapshot",
+        AsyncMock(return_value=proxy_snapshot),
+    )
+
+    captured: dict[str, Any] = {}
+
+    async def _fake_execute_sync_json(
+        self: object,
+        plan: Any,
+    ) -> RustExecutorSyncResult:
+        captured["plan"] = plan
+        return RustExecutorSyncResult(
+            status_code=200,
+            response_json={"id": "resp_1", "usage": {"prompt_tokens": 1, "completion_tokens": 2}},
+            headers={"content-type": "application/json"},
+        )
+
+    monkeypatch.setattr(rust_mod.RustExecutorClient, "execute_sync_json", _fake_execute_sync_json)
+
+    result = await executor.execute(
+        EndpointCheckRequest(
+            url="https://upstream.test/v1/chat/completions",
+            headers={"authorization": "Bearer test"},
+            json_body={"model": "gpt-test", "messages": [{"role": "user", "content": "hi"}]},
+            api_format="openai:chat",
+            provider_name="openai",
+            model_name="gpt-test",
+            api_key_id="key_1",
+            provider_id="provider_1",
+        )
+    )
+
+    assert result.status_code == 200
+    assert result.response_data == {
+        "id": "resp_1",
+        "usage": {"prompt_tokens": 1, "completion_tokens": 2},
+    }
+    assert captured["plan"].proxy is proxy_snapshot
+    assert captured["plan"].method == "POST"
+    assert captured["plan"].url == "https://upstream.test/v1/chat/completions"
+
+
+@pytest.mark.asyncio
+async def test_endpoint_checker_stream_prefers_rust_executor(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    from src.api.handlers.base import endpoint_checker as mod
+    from src.services.request import rust_executor_client as rust_mod
+
+    monkeypatch.setattr(mod.config, "executor_backend", "rust")
+
+    executor = HttpRequestExecutor(timeout=15.0)
+    monkeypatch.setattr(
+        executor,
+        "_build_rust_proxy_snapshot",
+        AsyncMock(return_value=None),
+    )
+
+    async def _byte_iter() -> Any:
+        yield b'data: {"choices":[{"delta":{"content":"Hel'
+        yield b'lo"}}]}\n\n'
+        yield b'data: {"choices":[{"delta":{"content":" world"},"finish_reason":"stop"}]}\n\n'
+
+    stream_ctx = _DummyStreamContext()
+
+    async def _fake_execute_stream(self: object, plan: Any) -> RustExecutorStreamResult:
+        return RustExecutorStreamResult(
+            status_code=200,
+            headers={"content-type": "text/event-stream"},
+            byte_iterator=_byte_iter(),
+            response_ctx=stream_ctx,
+        )
+
+    monkeypatch.setattr(rust_mod.RustExecutorClient, "execute_stream", _fake_execute_stream)
+
+    result = await executor.execute(
+        EndpointCheckRequest(
+            url="https://upstream.test/v1/chat/completions",
+            headers={"authorization": "Bearer test"},
+            json_body={
+                "model": "gpt-test",
+                "messages": [{"role": "user", "content": "hi"}],
+                "stream": True,
+            },
+            api_format="openai:chat",
+            provider_name="openai",
+            model_name="gpt-test",
+            is_stream=True,
+        )
+    )
+
+    assert result.status_code == 200
+    assert result.response_data == {
+        "choices": [{"delta": {"content": " world"}, "finish_reason": "stop"}]
+    }
+    assert stream_ctx.closed is True
+
+
+@pytest.mark.asyncio
+async def test_endpoint_checker_proxy_snapshot_falls_back_to_system_proxy(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    from src.services.proxy_node import resolver as resolver_mod
+
+    executor = HttpRequestExecutor()
+
+    monkeypatch.setattr(
+        resolver_mod,
+        "get_system_proxy_config_async",
+        AsyncMock(return_value={"enabled": True, "url": "http://system-proxy.test:8080"}),
+    )
+    monkeypatch.setattr(
+        resolver_mod,
+        "resolve_delegate_config_async",
+        AsyncMock(return_value=None),
+    )
+    monkeypatch.setattr(
+        resolver_mod,
+        "build_proxy_url_async",
+        AsyncMock(return_value="http://system-proxy.test:8080"),
+    )
+    monkeypatch.setattr(
+        resolver_mod,
+        "resolve_proxy_info_async",
+        AsyncMock(return_value={"mode": "http", "label": "system-proxy"}),
+    )
+
+    snapshot = await executor._build_rust_proxy_snapshot(None)
+
+    assert snapshot is not None
+    assert snapshot.enabled is True
+    assert snapshot.url == "http://system-proxy.test:8080"
+    assert snapshot.mode == "http"