feat: show agent activity and simplify starter view

frontend/src/components/agent-activity-status.tsx

@@ -0,0 +1,25 @@
+import { ThinkingOrb, type OrbState } from "thinking-orbs";
+
+const labels = {
+  working: "正在处理任务…",
+  searching: "正在搜索相关信息…",
+  solving: "正在分析问题…",
+  listening: "正在聆听…",
+  composing: "正在组织回答…",
+  shaping: "正在生成结果…",
+} as const satisfies Record<OrbState, string>;
+
+export function AgentActivityStatus({
+  state,
+  label = labels[state],
+}: Readonly<{
+  state: OrbState;
+  label?: string;
+}>) {
+  return (
+    <div className="agent-activity-status" role="status">
+      <ThinkingOrb aria-hidden="true" state={state} size={20} />
+      <span>{label}</span>
+    </div>
+  );
+}

frontend/src/components/chat-message-row.tsx

@@ -1,3 +1,4 @@
+import { AgentActivityStatus } from "@/components/agent-activity-status";
 import { ChatMessageContent } from "@/components/chat-message-content";
 import type { ChatMessageView } from "@/lib/chat-message-view";
 
@@ -22,8 +23,11 @@ export function ChatMessageRow({ message }: { readonly message: ChatMessageView
         <div className="message-bubble">
           {message.role === "assistant" ? (
             message.state === "thinking"
-              ? <div className="thinking"><i /><i /><i /></div>
-              : <ChatMessageContent text={message.text} />
+              ? <AgentActivityStatus state="working" label="正在核对星盘信息…" />
+              : <>
+                {message.state === "streaming" && <AgentActivityStatus state="composing" />}
+                <ChatMessageContent text={message.text} />
+              </>
           ) : <p>{message.text}</p>}
         </div>
       </div>

frontend/src/components/parameter-freeze-panel.tsx

@@ -1,23 +0,0 @@
-export type ParameterFreezeRow = {
-  label: string;
-  value: string;
-};
-
-export function ParameterFreezePanel({ rows }: { readonly rows: readonly ParameterFreezeRow[] }) {
-  return (
-    <section className="parameter-freeze-panel" aria-label="当前排盘参数冻结">
-      <div>
-        <b>当前排盘参数</b>
-        <span>这些参数会随咨询一起送入证据链。</span>
-      </div>
-      <dl>
-        {rows.map((row) => (
-          <div key={row.label}>
-            <dt>{row.label}</dt>
-            <dd>{row.value}</dd>
-          </div>
-        ))}
-      </dl>
-    </section>
-  );
-}