I've been experimenting with this with a custom /plan slash command for claude code, available here: https://github.com/atomCAD/agents

Planning is definitely still something that requires a human in the loop, but I have been able to avoid the problem you are describing. It does require some trickery (not yet represented in the /plan command) when the overall plan exceeds reasonable context window size (~20k tokens). You basically have to start having the AI consider combinatorially many batches of the plan compared with each other, to discover and correct these dependency issues.