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App now registers -json only when App.JSON is true, so a CLI whose commands do not use cli.Emit never advertises a flag it cannot honor. Driven by the first real consumer (evpnc), whose commands print text directly and are not yet converted to Emit. The example opts in (JSON: true). Backward-additive: existing App users that want -json set JSON: true. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>