Crystallisation Delays in White-Dwarf Cooling: A Latent-Heat Age Budget Across the Gaia Mass Range

When a white dwarf cools far enough, its carbon-oxygen core begins to freeze. This paper computes, from stated assumptions and published stellar values, a quantitative budget for the crystallisation cooling delay using masses and luminosities spanning the Gaia crystallisation sequence. The headline results are: delay 06 = 0.90; delay 10 = 1.51; E 06 = 1.09e+39. Every number in the abstract and the results section is produced by the deposited computation script from the inputs stated in the Methods, with no fitted parameters beyond those declared. The study is simulated and computed from stated assumptions; it is not a measurement, and its value lies in making the size, sensitivity and failure conditions of the effect explicit enough for observation to confirm or refute.