Structured-Output-Picker — 在解码处约束，还是在校验处约束？ One-liner : Three local libraries (Outlines, Instructor, Guidance) plus provider-native structured outputs all "make the model emit valid structure", but they enforce at different points and fail differently . Pick by how costly a malformed output is and whether you control the decoder . Then pick the failure stance — Assert (hard-fail + retry) vs Suggest (soft nudge, degrade gracefully) — borrowed from DSPy's constraint primitives. This is an ENHANCE overlay . The four enforcement mechanisms each have a working local skill; what no single one provi…