fix: preserve investigation execution history by round

src/features/agent/api/client.ts

@@ -174,6 +174,8 @@ export type AgentApiClient = InteractionRequestApi & {
   moveSessionToTopic: (sessionId: string, topicId: string | null) => Promise<void>;
   loadOlderMessages: (sessionId: string, before: string, signal?: AbortSignal) => Promise<AgentHistoryMessagePage>;
   createTaskCollaborationSession: (taskId: string) => Promise<AgentChatSession>;
+  createTaskExecutionDebugSession: (taskId: string, runId: string, sessionId: string) => Promise<AgentChatSession>;
+  loadTaskExecutionSession: (taskId: string, runId: string, sessionId: string, signal?: AbortSignal) => Promise<AgentLoadedChatSession | null>;
   loadSession: (sessionId: string, options?: { messageLimit?: number; signal?: AbortSignal }) => Promise<AgentLoadedChatSession | null>;
   streamSession: (
     sessionId: string,
@@ -365,6 +367,30 @@ export function createAgentApiClient(
       );
     },
 
+    async createTaskExecutionDebugSession(taskId, runId, sessionId) {
+      return requestJson<AgentChatSession>(
+        `/task/${encodeURIComponent(taskId)}/execution-session/debug`,
+        {
+          method: "POST",
+          headers: { "Content-Type": "application/json" },
+          body: JSON.stringify({ run_id: runId, session_id: sessionId })
+        }
+      );
+    },
+
+    async loadTaskExecutionSession(taskId, runId, sessionId, signal) {
+      const query = new URLSearchParams({ run_id: runId, session_id: sessionId });
+      const response = await request(
+        `/task/${encodeURIComponent(taskId)}/execution-session?${query}`,
+        { signal }
+      );
+      const text = await response.text();
+      const data = text ? JSON.parse(text) : null;
+      if (response.status === 404) return null;
+      if (!response.ok) throw new Error(getResponseErrorMessage(data, response.status));
+      return toLoadedSession(data);
+    },
+
     async getFrontendActionRegistry() {
       return requestJson<unknown>("/frontend-action-registry");
     },