CDN-373: The Tidal Chirp Gate

CDN-373 tests whether crossing the CDN-372 tidal cadence window is sufficient to preserve two-body capture under fixed tensor amplitude. Using the same dimensionless 3D trace-free tidal tensor framework, this artifact holds tensor RMS fixed at C0=0.65 while replacing the fixed periodic cadence with chirped and gated tau(t) schedules. Fast-to-slow, slow-to-fast, early-window, middle-window, late-window, brief-pulse, fixed-window, and fixed-slow schedules are tested under coherent and random initial phase ensembles. The result shows that temporal order matters: capture fractions span 0.126953125 to 1.0, and early residence inside the high-capture cadence band correlates with capture at r = 0.9884129993727754. Passing through the window is not enough; the favorable cadence must arrive early enough to shape the local two-body evolution.