Recent detections of very-high-energy [(VHE) $\gtrsim 100\mathrm{GeV}$] photons from afterglows like gamma-ray burst (GRB) 221009A demand models that treat jet angular structure, circumburst stratification, and inverse Compton radiation self-consistently. We present a numerical afterglow framework in which a Gaussian structured jet decelerates as an adiabatic forward shock in a wind-stratified medium ($\rho \propto r^{-2}$), and compute broadband synchrotron and synchrotron self-Compton (SSC) emission. Our approach aims to connect a wind-stratified environment with a Gaussian angular jet profile and to explore SSC emission to predict VHE afterglow detectability with the Cherenkov Telescope Array (CTA). We find that the TeV peak time and peak flux are primarily governed by jet geometry (ratio of ${\theta }_v/{\theta }_c$), together with wind-driven blast-wave deceleration and jet microphysics. In particular, variations in the jet kinetic energy ($E_k$), wind density parameter ($A_{\star }$), and the ratio of microphysical parameters (${\epsilon }_e$ and ${\epsilon }_B$) can change the TeV flux by orders of magnitude. Using the CTAO North differential sensitivity at 250 GeV, we simulate $4\times {10}^4$ wind-Gaussian afterglows and find that only $\sim 10\%$ satisfy our detectability criterion, primarily for bursts with high $E_k$, moderate to high $A_{\star }$, high ${\epsilon }_e$, and low ${\epsilon }_B$, and near on-axis jet geometries (${\theta }_v/{\theta }_c\lesssim 2$). Finally, fitting the multiband afterglow of GRB 221009A from radio to TeV, we obtain a mildly off-axis, SSC-dominated afterglow in a wind-driven medium that reproduces the observed broadband temporal evolution. The inferred parameters favor strong TeV SSC emission, implying that GRBs similar to GRB 221009A should be detectable by CTA.

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• Gamma ray bursts