UDCT v5.58: Pre-registration of Option O8c (Compactness-Screened MOND)

Pre-registration of option O8c, not a result. At deposit no O8c prediction has been computed.O8c keeps MOND-type enhancement where the dimensionless tidal invariant X = c²|T|/|g_N|² is below X* = 4×10⁹ and screens it above. Base law ν₀(x) = (1+1/x)1/2 with ξ₀ = 1.082401×10⁻¹⁰ m s⁻² (not refitted); switch S = 1/(1+(X/X*)⁴); QUMOND field equation.Gate order: D2 (explicit action) → D3 → D5 (Cassini Q₂ ≤ 0.52×10⁻²⁶ s⁻², Saturn |δa| < 10⁻¹⁴ m s⁻²) → D8 (wide binaries reported; ultra-faint dwarfs kill gate, Simon 2019 sample) → D6 (weak-lensing RAR) → D4 (v5.50 SPARC protocol, S ≤ +10).Blindness is partial: X* was located using SPARC baryonic geometry (v5.57), and SPARC rotation curves were opened earlier for other laws. The ultra-faint-dwarf risk is declared in advance. Passing the gates would not validate UDCT.