feat: Antigravity 和 Codex 服务支持

- 新增 Antigravity 服务：签名缓存、URL 可用性检测、信封处理
- 新增 Codex 服务：信封处理、元数据收集器
- 重构 provider transport 支持新的服务架构
- 新增 stream_bridge 和 upstream_stream_bridge 处理流式响应
- 优化 OAuth 工具函数
- 添加相关测试用例

tests/services/antigravity/test_client.py

@@ -0,0 +1,36 @@
+from __future__ import annotations
+
+from types import SimpleNamespace
+from unittest.mock import AsyncMock, patch
+
+import httpx
+import pytest
+
+from src.services.antigravity.client import load_code_assist
+from src.services.antigravity.constants import DAILY_BASE_URL, PROD_BASE_URL
+
+
+@pytest.mark.asyncio
+async def test_load_code_assist_falls_back_to_daily() -> None:
+    resp1 = httpx.Response(500, json={"error": {"message": "boom"}})
+    resp2 = httpx.Response(200, json={"cloudaicompanionProject": "project-1"})
+
+    client = SimpleNamespace(post=AsyncMock(side_effect=[resp1, resp2]))
+
+    with patch(
+        "src.clients.http_client.HTTPClientPool.get_proxy_client",
+        AsyncMock(return_value=client),
+    ):
+        data = await load_code_assist("tok", proxy_config=None, timeout_seconds=1.0)
+
+    assert data["cloudaicompanionProject"] == "project-1"
+    assert client.post.await_count == 2
+    assert client.post.call_args_list[0].args[0] == f"{PROD_BASE_URL}/v1internal:loadCodeAssist"
+    assert client.post.call_args_list[1].args[0] == f"{DAILY_BASE_URL}/v1internal:loadCodeAssist"
+
+
+@pytest.mark.asyncio
+async def test_load_code_assist_requires_token() -> None:
+    with pytest.raises(ValueError):
+        await load_code_assist("", proxy_config=None)
+

tests/services/antigravity/test_signature_cache.py

@@ -0,0 +1,35 @@
+from __future__ import annotations
+
+from src.services.antigravity.constants import DUMMY_THOUGHT_SIGNATURE
+from src.services.antigravity.signature_cache import ThinkingSignatureCache
+
+
+def test_get_or_dummy_returns_dummy_for_gemini_models() -> None:
+    cache = ThinkingSignatureCache(maxsize=10)
+    assert cache.get_or_dummy("gemini-3-pro", "thinking...") == DUMMY_THOUGHT_SIGNATURE
+
+
+def test_get_or_dummy_returns_none_for_non_gemini_models() -> None:
+    cache = ThinkingSignatureCache(maxsize=10)
+    assert cache.get_or_dummy("claude-sonnet", "thinking...") is None
+
+
+def test_cached_signature_preferred() -> None:
+    cache = ThinkingSignatureCache(maxsize=10)
+    cache.cache("gemini-3-pro", "t", "sig-1")
+    assert cache.get_or_dummy("gemini-3-pro", "t") == "sig-1"
+
+
+def test_eviction_fifo() -> None:
+    cache = ThinkingSignatureCache(maxsize=4)
+    cache.cache("gemini-3-pro", "t1", "s1")
+    cache.cache("gemini-3-pro", "t2", "s2")
+    cache.cache("gemini-3-pro", "t3", "s3")
+    cache.cache("gemini-3-pro", "t4", "s4")
+
+    # Trigger eviction (evict 1 key when maxsize=4)
+    cache.cache("gemini-3-pro", "t5", "s5")
+
+    # Oldest key should be gone
+    assert cache.get_or_dummy("gemini-3-pro", "t1") == DUMMY_THOUGHT_SIGNATURE
+

tests/services/antigravity/test_thinking_signature_conversion.py

@@ -0,0 +1,118 @@
+from __future__ import annotations
+
+from src.api.handlers.base.utils import get_format_converter_registry
+from src.services.antigravity.constants import DUMMY_THOUGHT_SIGNATURE
+from src.services.antigravity.signature_cache import signature_cache
+
+
+def _reset_sig_cache() -> None:
+    # Module-global cache; tests must isolate state.
+    signature_cache._cache.clear()  # type: ignore[attr-defined]
+
+
+def test_antigravity_converts_claude_thinking_block_to_gemini_thought_part_prefers_payload_sig() -> None:
+    _reset_sig_cache()
+
+    req = {
+        "model": "gemini-3-pro",
+        "max_tokens": 64,
+        "thinking": {"type": "enabled", "budget_tokens": 1000},
+        "messages": [
+            {"role": "user", "content": [{"type": "text", "text": "hi"}]},
+            {
+                "role": "assistant",
+                "content": [
+                    {"type": "thinking", "thinking": "t1", "signature": "sig-1"},
+                    {"type": "text", "text": "ok"},
+                ],
+            },
+        ],
+    }
+
+    registry = get_format_converter_registry()
+    out = registry.convert_request(req, "claude:chat", "gemini:cli", target_variant="antigravity")
+
+    assert isinstance(out.get("contents"), list)
+    model_turn = out["contents"][1]
+    assert model_turn["role"] == "model"
+    parts = model_turn["parts"]
+    assert parts[0]["thought"] is True
+    assert parts[0]["text"] == "t1"
+    assert parts[0]["thoughtSignature"] == "sig-1"
+
+
+def test_antigravity_uses_dummy_signature_for_gemini_when_missing() -> None:
+    _reset_sig_cache()
+
+    req = {
+        "model": "gemini-3-pro",
+        "max_tokens": 64,
+        "thinking": {"type": "enabled", "budget_tokens": 1000},
+        "messages": [
+            {"role": "user", "content": [{"type": "text", "text": "hi"}]},
+            {
+                "role": "assistant",
+                "content": [
+                    {"type": "thinking", "thinking": "t2"},
+                    {"type": "text", "text": "ok"},
+                ],
+            },
+        ],
+    }
+
+    registry = get_format_converter_registry()
+    out = registry.convert_request(req, "claude:chat", "gemini:cli", target_variant="antigravity")
+
+    parts = out["contents"][1]["parts"]
+    assert parts[0]["thought"] is True
+    assert parts[0]["text"] == "t2"
+    assert parts[0]["thoughtSignature"] == DUMMY_THOUGHT_SIGNATURE
+
+
+def test_antigravity_drops_unsigned_thinking_for_non_gemini_models() -> None:
+    _reset_sig_cache()
+
+    req = {
+        "model": "claude-sonnet-4-5",
+        "max_tokens": 64,
+        "thinking": {"type": "enabled", "budget_tokens": 1000},
+        "messages": [
+            {"role": "user", "content": [{"type": "text", "text": "hi"}]},
+            {
+                "role": "assistant",
+                "content": [
+                    {"type": "thinking", "thinking": "t3"},
+                    {"type": "text", "text": "ok"},
+                ],
+            },
+        ],
+    }
+
+    registry = get_format_converter_registry()
+    out = registry.convert_request(req, "claude:chat", "gemini:cli", target_variant="antigravity")
+
+    parts = out["contents"][1]["parts"]
+    assert all(p.get("thought") is not True for p in parts)
+
+
+def test_antigravity_inserts_dummy_thought_for_last_assistant_when_thinking_enabled() -> None:
+    _reset_sig_cache()
+
+    req = {
+        "model": "gemini-3-pro",
+        "max_tokens": 64,
+        "thinking": {"type": "enabled", "budget_tokens": 1000},
+        "messages": [
+            {"role": "user", "content": [{"type": "text", "text": "hi"}]},
+            {"role": "assistant", "content": [{"type": "text", "text": "prefill"}]},
+        ],
+    }
+
+    registry = get_format_converter_registry()
+    out = registry.convert_request(req, "claude:chat", "gemini:cli", target_variant="antigravity")
+
+    parts = out["contents"][1]["parts"]
+    assert parts[0]["thought"] is True
+    assert parts[0]["thoughtSignature"] == DUMMY_THOUGHT_SIGNATURE
+    assert parts[1]["text"] == "prefill"
+

tests/services/antigravity/test_url_availability.py

@@ -0,0 +1,58 @@
+from __future__ import annotations
+
+import src.services.antigravity.url_availability as ua_mod
+from src.services.antigravity.constants import (
+    DAILY_BASE_URL,
+    PROD_BASE_URL,
+    URL_UNAVAILABLE_TTL_SECONDS,
+)
+from src.services.antigravity.url_availability import url_availability
+
+
+def _reset_state() -> None:
+    # Singleton: tests need to reset global state
+    with url_availability._mu:  # type: ignore[attr-defined]
+        url_availability._unavailable.clear()  # type: ignore[attr-defined]
+        url_availability._last_success = None  # type: ignore[attr-defined]
+
+
+def test_mark_success_priority() -> None:
+    _reset_state()
+
+    url_availability.mark_success(PROD_BASE_URL)
+    ordered = url_availability.get_ordered_urls(prefer_daily=True)
+
+    assert ordered[0] == PROD_BASE_URL
+
+
+def test_mark_unavailable_filters_url() -> None:
+    _reset_state()
+
+    url_availability.mark_unavailable(DAILY_BASE_URL)
+    ordered = url_availability.get_ordered_urls(prefer_daily=True)
+
+    assert ordered[0] == PROD_BASE_URL
+    assert url_availability.is_available(DAILY_BASE_URL) is False
+
+
+def test_ttl_recovery(monkeypatch) -> None:
+    _reset_state()
+
+    t0 = 1000.0
+    monkeypatch.setattr(ua_mod.time, "time", lambda: t0)
+    url_availability.mark_unavailable(PROD_BASE_URL)
+    assert url_availability.is_available(PROD_BASE_URL) is False
+
+    monkeypatch.setattr(ua_mod.time, "time", lambda: t0 + URL_UNAVAILABLE_TTL_SECONDS + 1)
+    assert url_availability.is_available(PROD_BASE_URL) is True
+
+
+def test_all_unavailable_fallback_returns_base_order() -> None:
+    _reset_state()
+
+    url_availability.mark_unavailable(PROD_BASE_URL)
+    url_availability.mark_unavailable(DAILY_BASE_URL)
+
+    ordered = url_availability.get_ordered_urls(prefer_daily=True)
+    assert ordered == [DAILY_BASE_URL, PROD_BASE_URL]
+