feat(content): 发布体系 大/小图 + 公开 + 园区端发布

- 迁移0018：content_items 加 card_mode/is_public/source/tenant_id
- ContentRepository：_to_dict/create/update 含新字段；list 加 public_only/tenant_id 过滤
- /opc/content 仅 published+公开；/opc/content/{id} 非公开→404
- 园区端 POST /park/api/content：发布人强制=园区名、source=carrier、tenant=本园、is_public 默认false(仅大屏)、card_mode默认small
- 园区端 GET /park/api/content：本园区内容(含未公开)供大屏
- schemas 补 card_mode/is_public

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

app/api/routers/rbac_opc.py

@@ -92,8 +92,8 @@ async def opc_content(
     type: str = "news",
     db: Database = Depends(get_db),
 ):
-    """C 端资讯：type ∈ policy(政策)/news(资讯)/skill(技能)/dynamic(动态)，仅 published。公开浏览。"""
-    return {"items": await db.content.list(ctype=type, status="published")}
+    """C 端资讯：type ∈ policy/news/skill/dynamic，仅 published + 公开(is_public)。公开浏览。"""
+    return {"items": await db.content.list(ctype=type, status="published", public_only=True)}
 
 
 @router.get("/content/{content_id}", summary="资讯详情")
@@ -102,7 +102,7 @@ async def opc_content_detail(
     db: Database = Depends(get_db),
 ):
     item = await db.content.get(content_id)
-    if item is None or item.get("status") != "published":
+    if item is None or item.get("status") != "published" or not item.get("is_public"):
         raise HTTPException(status_code=404, detail="内容不存在")
     # 阅读数自增（每次详情浏览 +1）
     if item.get("status") == "published":

app/api/schemas/operator.py

@@ -93,6 +93,8 @@ class ContentCreateRequest(BaseModel):
     link: str = ""                  # 外链
     publisher_name: str = ""        # 发布人昵称（空则用操作者）
     publisher_avatar: str = ""      # 发布人头像
+    card_mode: str = "big"          # big 大图 | small 小图（运营端设）
+    is_public: bool = True          # 是否公开
     status: str = "draft"
 
 
@@ -113,6 +115,10 @@ class ContentUpdateRequest(BaseModel):
     link: str | None = None
     publisher_name: str | None = None
     publisher_avatar: str | None = None
+    card_mode: str | None = None
+    is_public: bool | None = None
+    source: str | None = None
+    tenant_id: str | None = None
     status: str | None = None