Heuristic two-barrier phase diagram for AGN jet lifecycles. The horizontal axis shows the dimensionless horizon-threading magnetic flux ϕ_BH (SANE→MAD); the vertical axis shows the escape parameter Ξ_env = t_on/t_bo, separating confined from escaping jets. Three regimes are schematically indicated: quiescent or weak systems (flux-starved SANE), frustrated or compact sources such as CSO/CSS objects (MAD jets confined by dense environments, Ξ_env ≲ 1), and classical large-scale radio galaxies (MAD jets that escape and inflate lobes, Ξ_env ≳ 1). Engine power and environmental permeability are independent axes: a jet can be powerful yet remain compact if the circumnuclear gas column is sufficiently high. The diagram classifies known phenomenology into physically motivated regions but does not predict population fractions (see Section 3 for discussion).