Module loop_detector 

Loop detection guardrail for the agent tool-call loop.

Monitors a sliding window of recent tool calls and their results to detect three repetitive patterns that indicate the agent is stuck:

1. Exact repeat — same tool + args called 3+ times consecutively.
2. Ping-pong — two tools alternating (A->B->A->B) for 4+ cycles.
3. No progress — same tool called 5+ times with different args but identical result hash each time.

Detection triggers escalating responses: Warning -> Block -> Break.