feat: Phase 1+2 — project setup and core infrastructure

- requirements.txt, config.yaml, .env, Dockerfile, docker-compose.yml
- app/core: config (YAML+env override), logging (JSON structured),
  exceptions (typed hierarchy), json_utils (Markdown fence stripping)
- app/clients: LLMClient ABC + ZhipuAIClient (run_in_executor),
  StorageClient ABC + RustFSClient (boto3 head_object for size check)
- app/main.py: FastAPI app with health endpoint and router registration
- app/core/dependencies.py: lru_cache singleton factories
- tests/conftest.py: mock_llm, mock_storage, test_app, client fixtures
- pytest.ini: asyncio_mode=auto
- 11 unit tests passing

app/clients/storage/base.py

@@ -0,0 +1,21 @@
+from abc import ABC, abstractmethod
+
+
+class StorageClient(ABC):
+    @abstractmethod
+    async def download_bytes(self, bucket: str, path: str) -> bytes:
+        """Download an object and return its raw bytes."""
+
+    @abstractmethod
+    async def upload_bytes(
+        self, bucket: str, path: str, data: bytes, content_type: str = "application/octet-stream"
+    ) -> None:
+        """Upload raw bytes to the given bucket/path."""
+
+    @abstractmethod
+    async def get_presigned_url(self, bucket: str, path: str, expires: int = 3600) -> str:
+        """Return a presigned GET URL valid for `expires` seconds."""
+
+    @abstractmethod
+    async def get_object_size(self, bucket: str, path: str) -> int:
+        """Return the object size in bytes without downloading it."""

app/clients/storage/rustfs_client.py

@@ -0,0 +1,70 @@
+import asyncio
+import io
+
+import boto3
+from botocore.exceptions import ClientError
+
+from app.clients.storage.base import StorageClient
+from app.core.exceptions import StorageError
+from app.core.logging import get_logger
+
+logger = get_logger(__name__)
+
+
+class RustFSClient(StorageClient):
+    def __init__(self, endpoint: str, access_key: str, secret_key: str) -> None:
+        self._s3 = boto3.client(
+            "s3",
+            endpoint_url=endpoint,
+            aws_access_key_id=access_key,
+            aws_secret_access_key=secret_key,
+        )
+
+    async def download_bytes(self, bucket: str, path: str) -> bytes:
+        loop = asyncio.get_event_loop()
+        try:
+            resp = await loop.run_in_executor(
+                None, lambda: self._s3.get_object(Bucket=bucket, Key=path)
+            )
+            return resp["Body"].read()
+        except ClientError as exc:
+            raise StorageError(f"存储下载失败 [{bucket}/{path}]: {exc}") from exc
+
+    async def upload_bytes(
+        self, bucket: str, path: str, data: bytes, content_type: str = "application/octet-stream"
+    ) -> None:
+        loop = asyncio.get_event_loop()
+        try:
+            await loop.run_in_executor(
+                None,
+                lambda: self._s3.put_object(
+                    Bucket=bucket, Key=path, Body=io.BytesIO(data), ContentType=content_type
+                ),
+            )
+        except ClientError as exc:
+            raise StorageError(f"存储上传失败 [{bucket}/{path}]: {exc}") from exc
+
+    async def get_presigned_url(self, bucket: str, path: str, expires: int = 3600) -> str:
+        loop = asyncio.get_event_loop()
+        try:
+            url = await loop.run_in_executor(
+                None,
+                lambda: self._s3.generate_presigned_url(
+                    "get_object",
+                    Params={"Bucket": bucket, "Key": path},
+                    ExpiresIn=expires,
+                ),
+            )
+            return url
+        except ClientError as exc:
+            raise StorageError(f"生成预签名 URL 失败 [{bucket}/{path}]: {exc}") from exc
+
+    async def get_object_size(self, bucket: str, path: str) -> int:
+        loop = asyncio.get_event_loop()
+        try:
+            resp = await loop.run_in_executor(
+                None, lambda: self._s3.head_object(Bucket=bucket, Key=path)
+            )
+            return resp["ContentLength"]
+        except ClientError as exc:
+            raise StorageError(f"获取文件大小失败 [{bucket}/{path}]: {exc}") from exc