Loop Pipeline Router

The conditional-edge routing that turns a validate node into a bounded self-correcting loop (Ch5 Loop Pipeline + Error-handling strategies, Examples 5-6/5-9). Consumes a validation result, an error severity (correctable vs fundamental), and a retry budget, and returns exactly one of: proceed, refine (loop back with a remaining retry), fallback (alternative strategy once retries are exhausted), or terminate-with-partial (fundamental error). The finite retry budget is the explicit bound that prevents infinite loops. Use when first-attempt success is unrealistic and validation can identify correctable errors — plan refinement, documentation-gap re-requests, transient-failure…