muxr v3.7.0 Additive fail-loud + config-skew guardrails (v4 program, Phase 2). Non-breaking; rolls to every machine via the mise pin. - feat: schema_version forward-compat floor (fails loud with "upgrade muxr") - feat: read-path lint (fs::read banned outside primitives.rs) - fix: primitives::read_text is the sole file-read path - fix: corrupt state.json no longer silently cold-launches (session_id_for) - fix: missing configured harness prompt file fails loud; recycle composes before kill so a compose failure can't destroy the session - fix: unparseable campaign.md warns-and-skips instead of vanishing