We present BIT Galaxy — a framework derived from Boundary Information Theory (BIT) — that proposes a set of physically-grounded thresholds for galaxy classification, replacing the conventional values established in the 1970s. The central claim is that galaxies self-organize around a universal coherence attractor x* = 0.616, derived analytically from the self-consistent equation x = 1 - exp(-lambda*x) at lambda_c = 1.554, without free parameters. We show that this constant predicts: (1) a natural Low Surface Brightness (LSB) threshold at SB* = 23.43 mag/arcsec^2, compared to the conventional Freeman (1970) value of 22.5; (2) a natural flat rotation curve threshold at V_flat > 60-70 km/s, compared to the conventional 120 km/s; and (3) a network survival threshold LCC* = 0.616 in BIT-X∞ network dynamics. Cross-validation with SPARC (175 galaxies) and THINGS (34 galaxies) data yields a consistent coherence attractor at C* = 0.880 +/- 0.013, which we interpret as the empirical realization of x* = 0.616 under Toomre-based mapping. Five falsifiable predictions are provided for independent verification. This is a working paper submitted for open peer review. All data and code are available at [GitHub repository].