Memory leak with dynamic sub agent middleware

Hi,

I've implemented the dymanic middleware in my harness earlier, at https://github.com/avoidwork/madz/blob/main/src/agent/deepAgents.js#L249

In the past 2 days, with DeepSeek-V4-Flash running in madz, I've had crippling memory leaks - it looks like a more capable LLM has found a significant issue in the lib/middleware - it looks like it just keeps spawning - I haven't done a proper RCA yet though; I just woke up + got a coffee + found this:

Memory usage was flat before I added the dynamic middleware with DeepSeek-V4-Flash. I also want to point out I don't see this memory leak manifest with other LLMs like the Qwen family - I think DeepSeek-V4-Flash is simply doing something "better" which has found an edge case in the lib.

Start by reproducing the memory growth with the dynamic middleware and DeepSeek-V4-Flash, then compare it with the Qwen behavior described in the issue. Inspect lib/middleware alongside the linked harness entry point at src/agent/deepAgents.js#L249. Done means identifying the repeated spawning or retention path and confirming that memory remains stable after the fix.

Written by the indexing model from the issue text.