Two of the most profound unresolved challenges in contemporary physics are the ontological nature of the dark sector and the ultraviolet divergence in quantum gravity. This paper proposes an alternative ontology: the vacuum is not an empty geometric manifold, but a continuous, incompressible superfluid medium (the "Yuanzhi" field) characterized by an extreme bulk modulus Kyz and a microscopic healing length ξ. Within this framework, fundamental particles are identified as stable topological vortex excitations (knots) of the medium, while gravity emerges naturally as an isotropic macroscopic pressure gradient, and quantum entanglement is strictly governed by the global curvature of the Madelung quantum potential. Through a strict, no-free-parameter geometric derivation, this paper yields the electron rest mass scaling formula me = 1 2πMP (lP /Lknot) ≈ 0.511 MeV. Furthermore, the dark energy density is analytically derived as the acoustic Casimir pressure of vacuum fluctuations subject to the ξ cutoff, yielding B = π2 90 ℏc/ξ4. To distinguish this fluid dynamics model from established paradigms, we present four independent, testable observational predictions: (1) The spatial anisotropy ofthe GZK cutoff energy correlated with local cosmic void densities; (2) The anomalous precession in Lunar Laser Ranging (LLR) induced by fluid shear drag; (3) The doublehorn caustic optical signatures of Bose-Einstein Condensate (BEC) quantum vortex lenses in dark matter halos; (4) The annual modulation of diurnal clock biases in GEO satellites. For the latter, we propose a partial correlation analysis demonstrating that the clock drift amplitude correlates significantly with solar wind velocity (Vsw) rather than solar radio flux (F10.7), providing a crucial experimental discriminator against conventional thermal noise models.