feat: error handling, retry with backoff, and circuit breaker

Add robust error handling to the evolution loop and LLM adapters:
- Retry utility with exponential backoff for transient errors (429, 5xx, timeouts)
- Per-call error isolation in evaluator and judge adapter
- Circuit breaker in EvolutionLoop (trips after N consecutive failures)
- CLI flags: --max-retries, --error-strategy (skip|retry|abort)
- Config fields: max_retries, retry_delay_base, circuit_breaker_threshold, error_strategy
- 16 new unit tests covering all error handling paths

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/prometheus/application/use_cases.py

@@ -51,6 +51,8 @@ class OptimizePromptUseCase:
             minibatch_size=config.minibatch_size,
             perfect_score=config.perfect_score,
             verbose=config.verbose,
+            circuit_breaker_threshold=config.circuit_breaker_threshold,
+            error_strategy=config.error_strategy,
         )
         seed_prompt = Prompt(text=config.seed_prompt)
         state = loop.run(seed_prompt, synthetic_pool, config.task_description)