Switch background task loop detection from percentage-based sliding window (80% of 20-call window) to consecutive same-tool counting. Triggers when same tool signature is called 20+ times in a row; a different tool resets the counter.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>