feat(upload): 媒体上传优先走 OSS（OSS_ENDPOINT 启用→桶，返回 endpoint/bucket/key 绝对URL），本地降级

Co-Authored-By: Claude <noreply@anthropic.com>

app/services/media_upload.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
-"""媒体上传（图片/pdf/doc 等）—— 存 serverdata/uploads，返回绝对 URL。
+"""媒体上传（图片/pdf/doc 等）—— OSS 优先（OSS_ENDPOINT 配置后走桶），否则落 serverdata/uploads。
 
-与 app/training/main.py 的 /api/upload 共用同一目录与返回契约 {ok, url}。
+统一返回契约：绝对 URL。编辑器图片/视频/封面、C端资料上传共用。
 """
 from __future__ import annotations
 
@@ -10,8 +10,9 @@ import time
 from pathlib import Path
 
 from fastapi import HTTPException, UploadFile
+from .. import config
 
-# server-data 上传目录（server-core 根下 serverdata/uploads）
+# server-data 上传目录（server-core 根下 serverdata/uploads，本地降级用）
 SERVER_CORE_DIR = Path(__file__).resolve().parents[2]
 UPLOAD_DIR = SERVER_CORE_DIR / "serverdata" / "uploads"
 UPLOAD_DIR.mkdir(parents=True, exist_ok=True)
@@ -22,6 +23,14 @@ PUBLIC_BASE = __import__("os").environ.get("PUBLIC_BASE", "https://opc.pinesound
 ALLOWED_EXT = {".jpg", ".jpeg", ".png", ".webp", ".gif", ".pdf", ".doc", ".docx"}
 MAX_SIZE = 20 * 1024 * 1024  # 20MB
 
+# 扩展名 → content-type
+_MIME = {
+    ".jpg": "image/jpeg", ".jpeg": "image/jpeg", ".png": "image/png",
+    ".webp": "image/webp", ".gif": "image/gif",
+    ".pdf": "application/pdf", ".doc": "application/msword",
+    ".docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+}
+
 
 def abs_url(u: str | None) -> str:
     """相对路径补全为绝对 URL；已是完整 URL 或空则原样返回。"""
@@ -33,8 +42,14 @@ def abs_url(u: str | None) -> str:
     return PUBLIC_BASE + u
 
 
+def _oss_url(key: str) -> str:
+    """OSS 对象 -> 可访问绝对 URL（公共读桶 endpoint/bucket/key）。"""
+    endpoint = (config.OSS_ENDPOINT or "").rstrip("/")
+    return f"{endpoint}/{config.OSS_BUCKET}/{key}"
+
+
 async def save_media(file: UploadFile) -> str:
-    """保存上传文件到 uploads 目录，返回绝对 URL；不合法抛 400/413。"""
+    """保存上传文件：OSS 优先，否则本地 uploads；返回绝对 URL；不合法抛 400/413。"""
     name = (file.filename or "").rsplit("/", 1)[-1]
     ext = ("." + name.split(".")[-1].lower()) if "." in name else ""
     if ext not in ALLOWED_EXT:
@@ -43,6 +58,12 @@ async def save_media(file: UploadFile) -> str:
     if len(payload) > MAX_SIZE:
         raise HTTPException(status_code=413, detail="文件超过 20MB 限制")
     fname = f"up_{int(time.time())}_{secrets.token_hex(2)}{ext}"
+
+    if config.OSS_ENDPOINT and config.OSS_SECRET_KEY and config.OSS_ACCESS_KEY:
+        from ..infrastructure.oss import OSS
+        path = await OSS().upload(fname, payload, content_type=_MIME.get(ext, "application/octet-stream"))
+        # upload 返回 /oss/<key> 或 /uploads/<key>——OSS 桶走 endpoint/bucket/key
+        return _oss_url(fname)
     with open(UPLOAD_DIR / fname, "wb") as f:
         f.write(payload)
     return abs_url(f"/uploads/{fname}")