RUNNER: idle
This 2D companion draws the same test-matrix model as the 3D version as a flat heatmap grid instead of rotating 3D bars: rows are code modules (launch angle), columns are test cases (launch speed), and each cell's projectile trajectory is checked against a closed-form analytic baseline via Root Mean Square Error, exactly like a CI/CD pipeline regression-testing a physics model after a code change. This version adds CI flakiness — independent random noise applied to each case on every rerun — and reruns the whole suite several times, flagging any case whose verdict flips between reruns as a flaky test, so you can see coverage, pass rate and flaky-test detection update live as the suite sweeps the grid.