fix(physics): #265 landing-bounce family - retail check_contact seed + velocity-free landing commit

Retail jump landings BOUNCE: the floor touch records both a contact plane
(grounding) AND a collision normal (collided_with_environment), and
handle_all_collisions reflects the unmodified impact velocity off it at
5% elasticity (v += -(v.n)(elasticity+1).n, DEFAULT_ELASTICITY 0.05
@0x007c6a7c). Our transition already recorded both facts; the bounce was
suppressed by the AD-25 adaptation stack in the per-tick commit: a
Velocity.Z<=0 landing gate (needed because the resolver glued ascending
movers to the ground) plus a landing Velocity.Z=0 hand-zero whose stated
purpose was making the reflect a no-op. Downhill glided instead of
bouncing, flat-ground landings had no pop, and uphill jumps flapped
between grounded/airborne against the animation machine.

Three retail mechanisms replace the stack:
- check_contact (0x0050f5b0) seeding in ResolveWithTransition: a body in
  CONTACT seeds the transition's contact only while v.contactPlane.N <=
  0.0002; moving away seeds the last-known plane alone (get_object_info
  0x00511cc0). Ascending jumps therefore run contact-free (ballistic, no
  glue) - the gate's reason-for-being is gone. The plane requirement is
  strict: Contact-without-plane is unrepresentable in retail.
- SetPositionInternal-shaped commit (0x00515330, byte-read end-to-end,
  velocity-sign-FREE): contact purely from the transition's contact
  plane, HitGround on the airborne->walkable edge, HandleAllCollisions
  with unmodified impact velocity. Whole commit gated on Ok &&
  candidateMoved (retail pc:283657 skips SetPositionInternal entirely
  when the candidate did not move) - a standing body's contact state is
  never re-derived, which is what keeps rest bit-stable (AD-41 updated).
- Byte decodes: gate override state&0x800000=Sledding, zero branch
  state&0x20000=Inelastic, reflect strictly dot<0 - our port already had
  all three correct.

Settle: real landings (>=0.25 m/s) bounce and decay geometrically;
smaller impacts are consumed by retail's unconditional small-velocity
zero, so standing never micro-bounces. Re-baselines documented in place:
landing-survival pin measures decay post-settle; LiveCompare_Tick0/376
pin the new IsOnGround=false on zero-move ticks (captured true was the
retired seed echo; tick 376's captured body carries an 11.8 m/s grounded
velocity from the deleted get_state_velocity-overwrite era); de-overlap
fixture now carries the plane real grounded bodies always have. New
pins: LandingBounceSeedingTests (ascent no-seed, rest keeps contact,
strict plane, slope 5% reversal + tangential preservation, Sledding
override).

Investigation + implementation record:
docs/research/2026-07-30-landing-bounce-family.md. Complete Release
suite: 10,031 passed / 5 skips / 0 failures.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/AcDream.App.Tests/UI/Layout/VitaeColorDumpProbe.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using AcDream.App.UI.Layout;
+using DatReaderWriter;
+using DatReaderWriter.Options;
+using Xunit;
+
+namespace AcDream.App.Tests.UI.Layout;
+
+// THROWAWAY probe (#268): dump the authored 0x1B font-color arrays for the
+// character-panel footer labels so we can read retail's vitae parenthetical
+// color (AppendTextWithFont color index 3, gmSkillUI 0x0049b972). Delete
+// after the color constant is captured.
+public sealed class VitaeColorDumpProbe
+{
+    [Fact]
+    public void Dump_footer_font_color_arrays()
+    {
+        var datDir = Environment.GetEnvironmentVariable("ACDREAM_DAT_DIR")
+            ?? Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile),
+                            "Documents", "Asheron's Call");
+        if (!Directory.Exists(datDir)) return;
+
+        var sb = new StringBuilder();
+        using var dats = new DatCollection(datDir, DatAccessType.Read);
+        foreach (uint layoutId in new[] { 0x2100002Eu, 0x2100002Cu })
+        {
+            var root = LayoutImporter.ImportInfos(dats, layoutId);
+            if (root is null) { sb.AppendLine($"layout {layoutId:X8}: NOT FOUND"); continue; }
+            sb.AppendLine($"=== layout {layoutId:X8} ===");
+            Walk(root, sb);
+        }
+
+        var outPath = Path.Combine(AppContext.BaseDirectory, "vitae-color-dump.txt");
+        File.WriteAllText(outPath, sb.ToString());
+        // Also drop a copy next to the repo artifacts when resolvable.
+        var repoCopy = Environment.GetEnvironmentVariable("ACDREAM_PROBE_OUT");
+        if (!string.IsNullOrEmpty(repoCopy))
+            File.WriteAllText(repoCopy, sb.ToString());
+    }
+
+    private static void Walk(ElementInfo e, StringBuilder sb)
+    {
+        if (e.TryGetEffectiveProperty(0x1Bu, out var color))
+        {
+            if (color.Kind == UiPropertyKind.Array && color.ArrayValue.Count > 1)
+            {
+                sb.Append($"element {e.Id:X8} 0x1B array[{color.ArrayValue.Count}]:");
+                for (int i = 0; i < color.ArrayValue.Count; i++)
+                {
+                    var v = color.ArrayValue[i];
+                    if (v.Kind == UiPropertyKind.Color)
+                    {
+                        var c = v.ColorValue;
+                        sb.Append($" [{i}]=A{c.Alpha:D3},R{c.Red:D3},G{c.Green:D3},B{c.Blue:D3}");
+                    }
+                    else
+                    {
+                        sb.Append($" [{i}]=kind:{v.Kind}");
+                    }
+                }
+                sb.AppendLine();
+            }
+            else if (color.Kind == UiPropertyKind.Color)
+            {
+                var c = color.ColorValue;
+                sb.AppendLine(
+                    $"element {e.Id:X8} 0x1B single: A{c.Alpha:D3},R{c.Red:D3},G{c.Green:D3},B{c.Blue:D3}");
+            }
+        }
+
+        foreach (var child in e.Children)
+            Walk(child, sb);
+    }
+}