fix(server): hide empty sessions from the import list

packages/server/src/server/agent/import-sessions.ts

@@ -123,6 +123,9 @@ export async function listImportableProviderSessions(
     if (isMetadataGenerationDescriptor(descriptor)) {
       continue;
     }
+    if (!hasUserPrompt(descriptor)) {
+      continue;
+    }
     const providerHandleId =
       descriptor.persistence.nativeHandle ?? descriptor.persistence.sessionId;
     if (importedHandles.has(toProviderSessionHandleKey(descriptor.provider, providerHandleId))) {
@@ -327,6 +330,12 @@ function isMetadataGenerationDescriptor(descriptor: PersistedAgentDescriptor): b
   return false;
 }
 
+function hasUserPrompt(descriptor: PersistedAgentDescriptor): boolean {
+  return descriptor.timeline.some(
+    (item) => item.type === "user_message" && item.text.trim() !== "",
+  );
+}
+
 function collectProviderSessionHandleKeys(
   target: Set<string>,
   provider: AgentProvider | StoredAgentRecord["provider"] | string,