PAPER XXVI — The "Officially Forgotten" Doubts: The Rift Between Einstein, Hawking, and the Dogma of the Singularity (Hydrodynamic Foundations of the Continuous Medium, the K.E.N.D.R.A. Layer, and the Causal Resolution of Ultra-Compact Collapses - Fluidons)

Contemporary relativistic astrophysics bases its treatment of compact objects on the ontological existence of zero-volume spacetime singularities and absolute event horizons. However, this paradigm omits a fundamental epistemological original fracture: in 1939, Albert Einstein formally demonstrated that a real material distribution cannot collapse indefinitely to the Schwarzschild radius without violating local causality ($v < c$), qualifying the singularity as a non-physical mathematical artifact. In the same year, the unlimited collapse model was introduced by Oppenheimer and Snyder solely by postulating a fictitious zero-pressure dust ($p=0$), establishing a conceptual double standard where pressure is arbitrarily zeroed out for integration convenience in the dynamical regime. The subsequent geometric reification promoted by J. A. Wheeler in 1967 under the media lemma of "black hole" generated decades of theoretical aporias, culminating in 2014 in the critical revision by Stephen Hawking, who formally excluded the existence of absolute horizons in favor of chaotic and transient interfaces. In continuity with the formal demonstrations developed in our previous corpus, this work reconnects the causal thread broken in 1939. Applying the principles of continuum mechanics and Zel'dovich's acoustic saturation (cₛ = c), the transient balance equation Tdt demonstrates that the halt of the collapse is imposed by the elastic back-pressure of the baryonic condensate, structured in the non-singular shear interface K.E.N.D.R.A. (Fluidon). The model avoids infinite density divergence and radically resolves the information paradox. Crucially, the Fluidon model finds direct empirical support in the latest 2026 observational data: the continuous population of the lower mass gap detected in the LIGO-Virgo-KAGRA O4 run (e.g., GW230529) via Color-Flavor Locking (CFL) superfluid transitions, and the paradoxical X-ray silence of supermassive "Little Red Dots" observed by JWST at $z > 10$, which confirms the non-radiative dissipation of kinetic energy by viscous shear stress within the K.E.N.D.R.A. layer. The paper establishes a rigorous protocol of Galilean falsifiability based on non-zero tidal deformability (k₂ > 0) and acoustic ringdown echoes in gravitational interferometric signals.