This arXiv preprint (v1, May 2026) constructs an end-to-end nonequilibrium pipeline anchored in dimensionless constants and nuclear resonances, converting them into falsifiable inequalities for free-energy flux, replication fidelity, and geologic cycle closure. Unlike mission-centric biosignature searches that treat habitability as a checklist of volatiles and insolation, the framework treats persistence as a quantifiable phase diagram whose margins propagate from the 12C Hoyle state and Landauer bound through Darwinian dynamics to net primary productivity. It is a purely theoretical construct with no empirical sample; limitations include explicit dependence on assumed solvent and chemistry families, rendering some gate rankings prior-dominated rather than observationally bounded. The approach exposes a gap in conventional coverage: transit spectroscopy can directly constrain the earliest gates (energy flux, reaction-transport rates) while later ecological-closure metrics require long-baseline climate data still absent from most target lists. Cross-referencing with England's dissipation-driven adaptation work and the 2015 NASA Astrobiology Strategy shows how this gate vector supplies the missing quantitative link between microscopic irreversibility and planetary-scale disequilibrium observables.