Dissipative Quantum Gravity: Black Hole Exceptional Horizons and Quantum Information Conservation

Open quantum substrate dynamics at black hole event horizons induce a second-order Exceptional Point (EP₂). Spacetime singularities are eliminated. This non-Hermitian boundary separates the PT-symmetric exterior from a dissipative PT-broken interior. Boundary matching at rEP = rₕ/(1-γ²) determines the regular two-scale interior lapse. At the origin, a smooth de Sitter core caps curvature invariants at K(0) = 24/P⁴. Thermal Hawking emission ceases at TH(rᵣₑₘ) = 0. This evaporation halt leaves a stable zero-temperature remnant with mass Mᵣₑₘ = 3√34P and a macroscopically divergent "Bag of Gold" interior volume Vᵢₙₜ → ∞. Stinespring's dilation theorem embeds the open interior into a global closed Hilbert space Hcore ⊗ Hrad, preserving global S-matrix unitarity. Non-Hermitian mode mixing near rEP alters the effective Regge-Wheeler potential, inducing a linear fractional frequency shift Δω/ω₀ ~ O(P/rₕ) that provides a distinctive ringdown signature for primordial black holes.