overset mesh: the flat-tip outline (P5-3 option B) — cylinder_flag_outline_deformed_tip / cylinder_flag_patch_deformed{,_from}_tip take the tip's corner radius (t = the recorded semicircle, bit for bit; smaller = the benchmark's flat face between corner arcs sampled at the wall spacing, point count fixed across the deformation, the tip's corners kept off the hull source); pins: corner t reproduces the recorded outline, the 2.5 mm outline has the exact area excess with no collapsed spacing, the O-grid builds straight and at ± 80 mm cold and warm at ny 41/62; harness knob RTX_FSI2O_TIP_CORNER (default 0.01) on the cold and warm builds, printed in both headers; pinned-toolchain fmt on touched crates

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01LzcjQX7tvgn87CQCyg9Cfr

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

@@ -100,7 +100,7 @@ pub fn run_march_overset(case: BenchmarkCase, config: &OversetMarchConfig) -> Ov
     // Every setting the acceptance rule reads, printed once: P5-3 lost a
     // day to a floor of 2e-4 against the overnight marches' 1e-6.
     println!(
-        "  coupling: {} (reuse {}, ω0 {}, c1 {}), floor {:.1e}, rtol {:.1e}, stall accept {:.1e}, max subit {}, predictor {}, s = {}, patch offset {} h × {} rows, patch convection {:?}, bg convection {:?}, patch stretch {}, fillet {} m",
+        "  coupling: {} (reuse {}, ω0 {}, c1 {}), floor {:.1e}, rtol {:.1e}, stall accept {:.1e}, max subit {}, predictor {}, s = {}, patch offset {} h × {} rows, patch convection {:?}, bg convection {:?}, patch stretch {}, fillet {} m, tip corner {} m",
         cfg.coupler,
         cfg.reuse,
         cfg.initial_relaxation,
@@ -117,6 +117,7 @@ pub fn run_march_overset(case: BenchmarkCase, config: &OversetMarchConfig) -> Ov
         super::overset::bg_convection(),
         super::overset::patch_stretch(),
         super::overset::fillet(),
+        super::overset::tip_corner(),
     );
 
     // Phase 1: rigid flag to t_release (`RTX_FSI2O_LOAD=dir` replaces the