This paper reinterprets Zitterbewegung as a physically real internal oscillation of the electron, rather than a mathematical artifact of the Dirac equation. Within this framework, the internal motion is confined to a photonic shell structure governed by the electron's Compton wavelength and evolves according to proper time. Building on previous work, the author derives a special relativistic estimate for the internal velocity v_e,SR = 0.040472c, subsequently refined to v_e,SR+GR = 0.040374c at Earth's surface by incorporating general relativistic effects including geodetic precession. A key prediction is that this velocity is subject to gravitational modulation, similar to GPS satellite clock corrections. The study predicts that Zitterbewegung frequency at satellite altitude would exceed that at Earth's surface by approximately 2.64 times 10^9 Hz due to gravitational redshift effects, representing a fractional frequency change of 5.29 times 10^-10. This demonstrates that electrons could function as relativistic quantum clocks sensitive to gravitational potentials. If verified experimentally, this would provide a novel connection between quantum internal dynamics and spacetime geometry, supporting the physical reality of Zitterbewegung and offering a new quantum-scale probe for exploring the intersection of quantum mechanics and general relativity.