feat(ui): add views for Responses (#2293)

# What does this PR do?
* Add responses list and detail views
* Refactored components to be shared as much as possible between chat
completions and responses

## Test Plan
<img width="2014" alt="image"
src="https://github.com/user-attachments/assets/6dee12ea-8876-4351-a6eb-2338058466ef"
/>
<img width="2021" alt="image"
src="https://github.com/user-attachments/assets/6c7c71b8-25b7-4199-9c57-6960be5580c8"
/>

added tests

llama_stack/ui/components/responses/utils/item-types.ts

@@ -0,0 +1,61 @@
+/**
+ * Type guards for different item types in responses
+ */
+
+import type {
+  ResponseInput,
+  ResponseOutput,
+  ResponseMessage,
+  ResponseToolCall,
+} from "@/lib/types";
+
+export interface BaseItem {
+  type: string;
+  [key: string]: unknown;
+}
+
+export type MessageItem = ResponseMessage;
+export type FunctionCallItem = ResponseToolCall & { type: "function_call" };
+export type WebSearchCallItem = ResponseToolCall & { type: "web_search_call" };
+export type FunctionCallOutputItem = BaseItem & {
+  type: "function_call_output";
+  call_id: string;
+  output?: string | object;
+};
+
+export type AnyResponseItem =
+  | ResponseInput
+  | ResponseOutput
+  | FunctionCallOutputItem;
+
+export function isMessageInput(
+  item: ResponseInput,
+): item is ResponseInput & { type: "message" } {
+  return item.type === "message";
+}
+
+export function isMessageItem(item: AnyResponseItem): item is MessageItem {
+  return item.type === "message" && "content" in item;
+}
+
+export function isFunctionCallItem(
+  item: AnyResponseItem,
+): item is FunctionCallItem {
+  return item.type === "function_call" && "name" in item;
+}
+
+export function isWebSearchCallItem(
+  item: AnyResponseItem,
+): item is WebSearchCallItem {
+  return item.type === "web_search_call";
+}
+
+export function isFunctionCallOutputItem(
+  item: AnyResponseItem,
+): item is FunctionCallOutputItem {
+  return (
+    item.type === "function_call_output" &&
+    "call_id" in item &&
+    typeof (item as any).call_id === "string"
+  );
+}