This paper introduces a unified spectral framework centered on the L-EFM operator—a synthesis of Laplace, Euler, Fourier, and Mellin transforms—to solve the Riemann Hypothesis (RH) and quantify prime number theory. The core discovery is the Universal Spectral Constant, which demonstrates that at the critical line ($\sigma=0.5$), the spectral coherence of any non-empty set of primes is exactly 0.500000. This invariance was empirically verified across 18 independent tests covering residue classes, twin primes, gap distributions, and density regions. Proof of the Riemann Hypothesis The proof relies on two main pillars: The Spectral Trap: The L-EFM operator is extremely sensitive to the real part of the complex argument ($\sigma$). Moving even 0.1 away from $\sigma=0.5$ causes the normalized Euler product to either diverge exponentially (toward $10^{66}$) or collapse to zero (toward $10^{-6}$). Only $\sigma=0.5$ is spectrally admissible. The Growth Lemma: Analytically, this behavior is governed by the Gelfand-Shilov ultradistribution space. The lemma proves that spectral eigenfunctions are only compatible with the space's symmetry constraints when $\sigma=0.5$, effectively confining all non-trivial zeros of the zeta function to the critical line. Spectral Quantifications For the first time in 265 years, classical qualitative theorems have been assigned specific spectral numbers: Universal Consistency: Results like Goldbach’s conjecture, Dirichlet’s theorem, and the Hardy-Littlewood conjecture all yield a coherence of 0.500000. Structural Variants: The Green-Tao theorem is quantified through a monotonic decay in coherence as progression lengths ($k$) increase (e.g., $0.8731$ for $k=3$ to $0.7442$ for $k=6$). Other Metrics: Chebyshev’s bias is measured at exactly 0.000000, while Cramér’s ratio is quantified at 0.468712. Deterministic AI Safety (H2E) The framework extends into applied AI through the H2E (Hyperbolic-Euclidean) governance framework. By applying the same spectral coherence principles, a safety threshold of $\Lambda=0.9583$ is derived from the primes below 13. This provides a deterministic, non-hardcoded method for certifying AI safety across text, audio, and vision modalities, achieving zero empirical violations and receiving UNESCO Elite certification. Open-Source Methodology The author bypasses traditional journal publication, citing the precedent of Grigori Perelman and the belief that "the proof is the code." The entire framework is implemented in two publicly available, SHA-256 audited Jupyter notebooks (LEFM-SUITE7PLUS and LEFM_NEXTGEN). These notebooks integrate the Sieve of Eratosthenes for exact prime enumeration with the L-EFM operator for spectral analysis, ensuring all results are fully reproducible using Deterministic Seed 123.