init: EasyScreen 电子菜单系统

- server: FastAPI 后端（多屏管理、素材上传、节目编排、客户端注册/配置/心跳/崩溃上报、管理台托管）
- android: Java 客户端（minSdk 23，全屏图片/视频轮播、远程配置、开机自启、崩溃上报）
- web: React + Vite + antd 管理台（屏幕/素材/节目管理）
- 屏幕设备 ID 关联机制、gunicorn 生产部署脚本

server/app/routers/admin_assets.py

@@ -0,0 +1,92 @@
+"""管理端：素材上传与管理。"""
+import os
+import uuid
+
+from fastapi import APIRouter, Depends, File, HTTPException, UploadFile
+from sqlalchemy import func, select
+from sqlalchemy.orm import Session
+
+from ..auth import get_current_user
+from ..config import get_server_config
+from ..database import get_db
+from ..models import Asset, PlaylistItem
+from ..schemas import AssetOut
+
+router = APIRouter(prefix="/api/assets", tags=["assets"], dependencies=[Depends(get_current_user)])
+
+_EXT_MAP = {
+    "image/jpeg": ".jpg",
+    "image/png": ".png",
+    "image/gif": ".gif",
+    "image/webp": ".webp",
+    "video/mp4": ".mp4",
+    "video/webm": ".webm",
+    "video/x-matroska": ".mkv",
+}
+
+
+@router.get("", response_model=list[AssetOut])
+def list_assets(db: Session = Depends(get_db)):
+    return db.scalars(select(Asset).order_by(Asset.created_at.desc())).all()
+
+
+@router.post("", response_model=AssetOut)
+async def upload_asset(file: UploadFile = File(...), db: Session = Depends(get_db)):
+    """上传图片/视频素材。"""
+    cfg = get_server_config()
+    content_type = file.content_type or ""
+    ext = _EXT_MAP.get(content_type)
+    if not ext:
+        raise HTTPException(status_code=400, detail=f"不支持的素材类型: {content_type or '未知'}")
+
+    max_bytes = cfg.get("max_upload_mb", 500) * 1024 * 1024
+    # 流式读取并限制大小
+    data = b""
+    while chunk := await file.read(1024 * 1024):
+        data += chunk
+        if len(data) > max_bytes:
+            raise HTTPException(status_code=413, detail=f"文件超过大小限制 {cfg['max_upload_mb']}MB")
+
+    filename = f"{uuid.uuid4().hex}{ext}"
+    upload_dir = os.path.abspath(os.path.join(os.path.dirname(os.path.dirname(os.path.dirname(__file__))), cfg.get("upload_dir", "./uploads")))
+    os.makedirs(upload_dir, exist_ok=True)
+    dest = os.path.join(upload_dir, filename)
+    with open(dest, "wb") as f:
+        f.write(data)
+
+    is_video = content_type.startswith("video/")
+    asset = Asset(
+        name=file.filename or filename,
+        type="video" if is_video else "image",
+        url=f"/media/{filename}",
+        size=len(data),
+        duration=0 if is_video else 10,  # 图片默认展示 10 秒
+    )
+    db.add(asset)
+    db.commit()
+    db.refresh(asset)
+    return asset
+
+
+@router.delete("/{asset_id}")
+def delete_asset(asset_id: int, db: Session = Depends(get_db)):
+    asset = db.get(Asset, asset_id)
+    if not asset:
+        raise HTTPException(status_code=404, detail="素材不存在")
+
+    used = db.scalar(select(func.count(PlaylistItem.id)).where(PlaylistItem.asset_id == asset_id))
+    if used:
+        raise HTTPException(
+            status_code=409,
+            detail=f"该素材正被 {used} 个节目引用，请先从节目中移除再删除",
+        )
+
+    cfg = get_server_config()
+    upload_dir = os.path.abspath(os.path.join(os.path.dirname(os.path.dirname(os.path.dirname(__file__))), cfg.get("upload_dir", "./uploads")))
+    file_path = os.path.join(upload_dir, os.path.basename(asset.url))
+    if os.path.exists(file_path):
+        os.remove(file_path)
+
+    db.delete(asset)
+    db.commit()
+    return {"ok": True}