White dwarf (WD) tidal disruption events (TDEs) provide a powerful and pristine "smoking-gun" signature for locating otherwise elusive intermediate-mass black holes (IMBHs). In this talk, I will present a comprehensive, steady-state accretion-disk model designed for these highly super-Eddington systems, where fallback rates can skyrocket to 105 to 109 times higher than standard main-sequence TDEs. We model the newly formed central engine by incorporating advanced high-energy physics, including nuclear burning, magnetic pressure, and advection-dominated flows regulated by powerful disk winds. Going beyond the disk, we couple this engine with the microphysics governing relativistic jets to explore nonthermal particle acceleration, high-energy neutrinos, and cosmic rays. We deliver the first joint predictions for the resulting multi-messenger emissions—spanning both thermal and nonthermal electromagnetic spectra, MeV-to-high-energy neutrino channels, cosmic-ray contributions, and low-frequency gravitational wave bursts (~0.1-1 Hz) tailored for next-generation decihertz space observatories. Finally, I will apply this grand unified framework to interpret the recently discovered fast X-ray transient EP250702a, demonstrating how its multi-wavelength evolution unveils the physics of super-Eddington accretion and jet formation around an IMBH.
