The Standard Model predicts a pervasive Cosmic Neutrino Background (C$\nu$B) decoupled at $T \sim 1$ MeV, with a temperature of $T_\nu \approx 1.95$ K and a specific density contribution ($N_{eff} \approx 3.046$). While the CMB power spectrum strongly favors the existence of this background via its anisotropic stress (free-streaming) signature, direct detection remains elusive due to the extremely low energy of relic neutrinos ($10^{-4}$ eV). Furthermore, some BBN and CMB analyses hint at a tension in $N_{eff}$ (preferring slightly lower or higher values depending on the dataset), and the lack of direct evidence leaves room for non-standard thermal histories or "dark radiation" components (Planck Collaboration 2018; PTOLEMY Collaboration 2019).