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/openai/test_video_rust_sync.py

@@ -0,0 +1,103 @@
+from __future__ import annotations
+
+from types import SimpleNamespace
+from unittest.mock import AsyncMock
+
+import httpx
+import pytest
+from fastapi.responses import JSONResponse
+
+import src.api.handlers.openai.video_handler as video_mod
+from src.api.handlers.openai.video_handler import OpenAIVideoHandler
+
+
+def _make_handler() -> OpenAIVideoHandler:
+    return OpenAIVideoHandler(
+        db=SimpleNamespace(),
+        user=SimpleNamespace(id="user-1"),
+        api_key=SimpleNamespace(id="api-key-1"),
+        request_id="req-video-sync-test",
+        client_ip="127.0.0.1",
+        user_agent="pytest",
+        start_time=0.0,
+    )
+
+
+@pytest.mark.asyncio
+async def test_handle_create_task_uses_rust_sync_helper(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    handler = _make_handler()
+    monkeypatch.setattr(video_mod.UsageService, "create_pending_usage", lambda *args, **kwargs: None)
+    monkeypatch.setattr(
+        handler._normalizer,
+        "video_request_to_internal",
+        lambda body: SimpleNamespace(model=str(body.get("model") or "sora-2")),
+    )
+
+    candidate = SimpleNamespace(provider=SimpleNamespace(name="provider-1", id="prov-1"))
+    endpoint = SimpleNamespace(
+        id="ep-1",
+        api_family="openai",
+        endpoint_kind="video",
+        base_url="https://api.openai.com",
+        body_rules=None,
+    )
+    provider_key = SimpleNamespace(id="key-1")
+
+    monkeypatch.setattr(
+        handler,
+        "_resolve_upstream_key",
+        AsyncMock(return_value=("upstream-key", endpoint, provider_key)),
+    )
+    monkeypatch.setattr(
+        handler,
+        "_build_upstream_url",
+        lambda base_url: "https://api.openai.com/v1/videos",
+    )
+    monkeypatch.setattr(
+        handler,
+        "_build_upstream_headers",
+        lambda original_headers, upstream_key, endpoint, **kwargs: {
+            "authorization": f"Bearer {upstream_key}"
+        },
+    )
+    monkeypatch.setattr(
+        video_mod.HTTPClientPool,
+        "get_default_client_async",
+        AsyncMock(side_effect=AssertionError("python fallback should not run")),
+    )
+
+    async def _fake_rust_sync(**kwargs: object) -> httpx.Response:
+        assert kwargs["method"] == "POST"
+        assert kwargs["url"] == "https://api.openai.com/v1/videos"
+        assert kwargs["provider_id"] == "prov-1"
+        assert kwargs["endpoint_id"] == "ep-1"
+        assert kwargs["key_id"] == "key-1"
+        assert kwargs["body"] == {"model": "sora-2", "prompt": "hello"}
+        return httpx.Response(
+            200,
+            request=httpx.Request("POST", str(kwargs["url"])),
+            json={"id": "ext-1"},
+        )
+
+    create_failed = AsyncMock()
+    monkeypatch.setattr(handler, "_try_rust_sync_http_response", _fake_rust_sync)
+    monkeypatch.setattr(handler, "_create_failed_task_and_usage", create_failed)
+
+    async def _fake_submit_with_failover(**kwargs: object) -> JSONResponse:
+        response = await kwargs["submit_func"](candidate)
+        assert response.status_code == 200
+        assert response.json()["id"] == "ext-1"
+        return JSONResponse(status_code=400, content={"error": {"message": "stop"}})
+
+    monkeypatch.setattr(handler, "_submit_with_failover", _fake_submit_with_failover)
+
+    response = await handler.handle_create_task(
+        http_request=SimpleNamespace(),
+        original_headers={},
+        original_request_body={"model": "sora-2", "prompt": "hello"},
+    )
+
+    assert response.status_code == 400
+    create_failed.assert_awaited_once()