mini: fix default model (#35515)

packages/opencode/src/session/title.ts

@@ -0,0 +1,11 @@
+const parentTitlePrefix = "New session - "
+const childTitlePrefix = "Child session - "
+const defaultTitle = /^(New session - |Child session - )\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/
+
+export function createDefaultTitle(child: boolean) {
+  return (child ? childTitlePrefix : parentTitlePrefix) + new Date().toISOString()
+}
+
+export function isDefaultTitle(title: string) {
+  return defaultTitle.test(title)
+}