feat: 完成input_context节点

app/schemas/request.py

@@ -0,0 +1,21 @@
+"""前端设计请求：原始需求、当前大屏及可选补充上下文"""
+
+from pydantic import Field
+
+from .base import ExtensibleModel, JsonObject, NonBlankString
+from .screen import Screen
+
+
+class RequestContext(ExtensibleModel):
+    selected_node_ids: list[NonBlankString] = Field(default_factory=list)
+    screen_id: NonBlankString | None = None
+    screen_revision: int | None = Field(default=None, ge=0)
+    conversation_id: NonBlankString | None = None
+
+
+class DesignRequest(ExtensibleModel):
+    prompt: NonBlankString
+    screen: Screen
+    context: RequestContext = Field(default_factory=RequestContext)
+    # 只预留 JSON 描述入口，暂不规定材料种类，也不读取文件或远程资源
+    attachments: list[JsonObject] = Field(default_factory=list)