rtx-fsi: pin FSI3's release response and settled cycle

Two tiers in the FSI2 pattern. The committed default (t_end 4.2) pins
the deterministic release response at the digit-stable measurement
(uy 10.7684 +- 23.5726 mm, ux -2.8982; +-35% bands, 2x onset-growth
floor against a measured 4.6x). The sticky-mask study configuration
(HYST>0, subcycle 2, t_end >= 8.4, ny 62 or 82) pins the settled
flapping cycle measured across two grids at t_end 8.5 / window(2.0):
uy amp in [38, 72] mm (measured 50.2 / 57.6; the un-flapped release
and every pre-hysteresis dead march sit far below, and the reference
+-34.9 sits OUTSIDE — landing inside the reference band is a loud
finding, not a regression), mids, crossing-frequency in [4.4, 6.8]
(covers the estimator's measured beat-scatter — the DFT puts both
grids at 5.4-5.6 vs ref 5.46), and drag MEDIAN in [380, 530]
(measured 454.0 vs ref 460.2). WindowStats gains drag/lift medians —
the honest central loads (the extreme-based mids are noise-dominated
at large deformation).

Band anchors computed exactly as the test computes them, replayed
offline against the run 7/8/10 CSVs (deterministic trajectories).
Verified: both committed defaults green with the release pins live,
trajectories digit-identical (FSI3's loads line gains the medians,
FSI2's output byte-identical). The t_end 8.5 study pin runs at both
grids are in flight.

Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2

crates/specialized/rtx-fsi/tests/fsi2_harness/march.rs

@@ -147,6 +147,13 @@ pub struct WindowStats {
     pub drag_amp: f64,
     pub lift_mid: f64,
     pub lift_amp: f64,
+    /// Window MEDIANS of the recorded loads — the honest central values
+    /// (the mid ± amp above are extreme-based and noise-dominated at
+    /// large deformation; the medians measured within 0.8% / 2.7% of
+    /// the FSI3 / FSI2 reference drags where the mids read 14% off or
+    /// worse).
+    pub drag_median: f64,
+    pub lift_median: f64,
     /// uy amplitude over the first / last quarter of the coupled march.
     pub amp_early: f64,
     pub amp_late: f64,
@@ -203,6 +210,8 @@ impl MarchResult {
             .unwrap_or(self.force_times.len() / 2);
         let (drag_mid, drag_amp) = mid_amp(&self.drag[force_start..]);
         let (lift_mid, lift_amp) = mid_amp(&self.lift[force_start..]);
+        let drag_median = median(&mut self.drag[force_start..].to_vec());
+        let lift_median = median(&mut self.lift[force_start..].to_vec());
         let quarter = self.uy.len() / 4;
         let (_, amp_early) = mid_amp(&self.uy[..quarter.max(1)]);
         let (_, amp_late) = mid_amp(&self.uy[self.uy.len() - quarter.max(1)..]);
@@ -217,6 +226,8 @@ impl MarchResult {
             drag_amp,
             lift_mid,
             lift_amp,
+            drag_median,
+            lift_median,
             amp_early,
             amp_late,
         }