feat(server,web): import and export Trace files in the trace viewer (#73)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

packages/web/src/api/endpoints.ts

@@ -57,6 +57,8 @@ import type {
   TaskCreateResponse,
   TraceAnalysisResponse,
   TraceEventsResponse,
+  TraceImportRequest,
+  TraceImportResponse,
   UiPrefs,
   UsageGroupBy,
   UsageResponse,
@@ -332,6 +334,23 @@ export const getAgentTraceAnalysis = (
       `/traces/${encodeURIComponent(sessionId)}/${index}/analysis`,
   );
 
+/** Trace file download URL: the server sets Content-Disposition attachment, usable directly in <a download>. */
+export const agentTraceDownloadUrl = (
+  projectId: string,
+  agentId: string,
+  sessionId: string,
+  index: number,
+): string =>
+  `/api/projects/${encodeURIComponent(projectId)}/agents/${encodeURIComponent(agentId)}` +
+  `/traces/${encodeURIComponent(sessionId)}/${index}/download`;
+
+/** Imports a Trace JSONL file (owner only); the response says where the file landed (sessionId / index / date). */
+export const importAgentTrace = (projectId: string, agentId: string, body: TraceImportRequest) =>
+  apiFetch<TraceImportResponse>(
+    `/api/projects/${encodeURIComponent(projectId)}/agents/${encodeURIComponent(agentId)}/traces/import`,
+    { method: "POST", body },
+  );
+
 // Usage statistics ----------------------------------------------------------------------
 
 export const getUsage = (