UED Reconstruction Programme — Paper 3: Light at the Source-Field-Observer Boundary

Paper 3 of the UED Reconstruction Programme reconstructs the classical optical regime from the source-field-observer boundary rather than from an assumed wave or particle ontology. It inherits the generic Structured Vacuum Energy (SVE) ripple architecture of Paper 2 and separates optical source activation, SVE/path transfer, and receiver realization. The resulting framework recovers finite optical delay, phase wavelength, phase and group delay, inverse-square geometric response, coherent interference, coherence loss, diffraction, reflection, refraction, evanescent boundary response, guided transmission, and polarization within the declared linear regime. A central result is the stationary-frequency no-shift theorem: a monochromatic input passed through a linear time-invariant optical path retains its temporal frequency, although amplitude, phase, orientation, and delay may change. Consequently, ordinary static attenuation or phase delay is insufficient by itself to generate redshift. The measured baseline optical speed c0c_0 is retained as a calibrated characteristic front speed for the optical-coupled SVE response without requiring a travelling photon or wave-object interpretation. Polarization experiments require an extension from a scalar ripple state to a two-component receiver-accessible optical orientation state. The paper does not derive photon discreteness, atomic emission, microscopic material optics, or a universal SVE optical energy density. These remain explicit downstream or open problems. Paper 3 therefore establishes the continuous optical reconstruction that Paper 4 must extend when addressing discrete photon events and quantized manifestation.