ETS-backed advisory budget tracking.

Tracks actual resource usage (turns, tokens, wall time) across episodes and recommends budgets based on historical p95 values. Does not automatically adjust budgets — advisory only.

Usage

# After episode completion:
Cyclium.AdaptiveBudget.record(:my_actor, :check_health, %{
  turns_used: 4,
  tokens_used: 8_500,
  wall_ms: 15_000
})

# Get recommendation:
Cyclium.AdaptiveBudget.recommend(:my_actor, :check_health)
# => %{max_turns: 8, max_tokens: 18_000, max_wall_ms: 45_000}

# Get detailed stats:
Cyclium.AdaptiveBudget.stats(:my_actor, :check_health)