feat(core): 添加共享 Protocol 端口

LLMProvider / VLMProvider / TelemetryRecorder，全部 runtime_checkable。

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/unit/test_core_protocols.py

@@ -0,0 +1,67 @@
+"""core/protocols.py 单元测试 — 验证 Protocol 可 runtime_checkable。"""
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any
+
+import pytest
+
+from core.protocols import LLMProvider, TelemetryRecorder, VLMProvider
+from core.types import LLMResponse
+
+
+class _FakeLLM:
+    async def chat(
+        self,
+        messages: list[dict[str, Any]],
+        *,
+        session_id: str | None = None,
+        parent_call_id: str | None = None,
+    ) -> LLMResponse:
+        return LLMResponse(
+            content="ok", thinking="", model="m", provider="p",
+            prompt_tokens=1, completion_tokens=1, latency_ms=1,
+            ttft_ms=None, max_inter_token_ms=None, cache_hit=False, call_id="c",
+        )
+
+
+class _FakeVLM:
+    async def chat_with_images(
+        self,
+        messages: list[dict[str, Any]],
+        images: list[str | Path],
+        *,
+        session_id: str | None = None,
+        parent_call_id: str | None = None,
+    ) -> LLMResponse:
+        return LLMResponse(
+            content="ok", thinking="", model="m", provider="p",
+            prompt_tokens=1, completion_tokens=1, latency_ms=1,
+            ttft_ms=None, max_inter_token_ms=None, cache_hit=False, call_id="c",
+        )
+
+
+class _FakeTelemetry:
+    async def record_llm_call(
+        self, *, call_id: str, parent_call_id: str | None, session_id: str | None,
+        model_name: str, provider: str, messages: str, response: str, thinking: str,
+        prompt_tokens: int, completion_tokens: int, latency_ms: int,
+        ttft_ms: float | None, max_inter_token_ms: float | None,
+        cache_hit: bool, error: str | None,
+    ) -> None:
+        pass
+
+
+def test_fake_llm_satisfies_protocol() -> None:
+    assert isinstance(_FakeLLM(), LLMProvider)
+
+def test_fake_vlm_satisfies_protocol() -> None:
+    assert isinstance(_FakeVLM(), VLMProvider)
+
+def test_fake_telemetry_satisfies_protocol() -> None:
+    assert isinstance(_FakeTelemetry(), TelemetryRecorder)
+
+def test_plain_object_does_not_satisfy() -> None:
+    assert not isinstance(object(), LLMProvider)
+    assert not isinstance(object(), VLMProvider)
+    assert not isinstance(object(), TelemetryRecorder)