@@ -124,7 +124,7 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show
   <a href="showcase/wheelbarrow/"><img src="showcase/wheelbarrow/preview.webp" width="24%" alt="Wheelbarrow: a wooden tray with walls of stacked boards and iron straps, a spoked wheel, rear legs, and handles on a dark studio floor" /></a>
   <a href="showcase/anvil/"><img src="showcase/anvil/preview.webp" width="24%" alt="Anvil: a dark forged-steel London-pattern anvil with a flared, squared waist on a hooped timber stump on a dark studio floor" /></a>
   <a href="showcase/water-trough/"><img src="showcase/water-trough/preview.webp" width="24%" alt="Water trough: a watertight wooden trough with plank ends, contained water, and trestle legs on a dark studio floor" /></a>
-  <a href="showcase/hitching-post/"><img src="showcase/hitching-post/preview.webp" width="24%" alt="Hitching post: a square timber post with a pyramidal cap, cross-arm, iron bands wrapped around it, and two hitching rings on a dark studio floor" /></a>
+  <a href="showcase/hitching-post/"><img src="showcase/hitching-post/preview.webp" width="24%" alt="Hitching post: a square timber post with a pyramidal cap, cross-arm, iron bands wrapped around it, two hitching rings and a nailed horseshoe on a dark studio floor" /></a>
   <a href="showcase/grindstone/"><img src="showcase/grindstone/preview.webp" width="24%" alt="Grindstone: a stone wheel on a timber A-frame with an iron axle, hubs, crank, and tray on a dark studio floor" /></a>
   <a href="showcase/hand-pump/"><img src="showcase/hand-pump/preview.webp" width="24%" alt="Hand pump: a matte black cast-iron village pump on a stepped wooden plinth with a spout and handle on a dark studio floor" /></a>
   <a href="showcase/signpost/"><img src="showcase/signpost/preview.webp" width="24%" alt="Signpost: a timber crossroads post with three painted fingerboards lettered MILLBROOK 2, OAKHAM 5 and FORD 1, iron straps, and a pyramidal cap on a dark studio floor" /></a>
 
@@ -207,9 +207,9 @@
     {
       "name": "hitching-post",
       "dir": "showcase/hitching-post",
-      "teaches": "A procedural hitching post (eaved cap, one rail, cup shoe, rings hung through eyes) through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.",
-      "alt": "A tall wooden hitching post with a pointed cap, a crossbar, two iron bands wrapped around the post and two iron rings.",
-      "witnessesFix": "Recomputed: 1680 tris, two materials with 114 wood and 742 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.500×0.149×1.246 m, zmin 0, hygiene and coplanar pairs 0, post seated at z 0.010, ring centerline error 0, bands 6.5 mm proud of the post, LOD ratios in band, convex collider 80 tris, non-empty glTF. --skip-decimate exits 9; --stray-vert and --twin-sole exit 15; --lift-z exits 16; --clip-ring and --sunk-bands exit 18; --short-post exits 19.",
+      "teaches": "A procedural hitching post (eaved cap, one rail, cup shoe, rings hung through eyes, a face-nailed horseshoe) through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.",
+      "alt": "A tall wooden hitching post with a pointed cap, a crossbar with two hung iron rings, iron bands, and a horseshoe nailed heels-up to its face.",
+      "witnessesFix": "Recomputed: 1852 tris, two materials with 114 wood and 828 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.500×0.149×1.246 m, zmin 0, hygiene and coplanar pairs 0, post seated at z 0.010, ring centerline error 0, bands 6.5 mm proud of the post, horseshoe biting 1.5 mm and 7.5 mm proud, LOD ratios in band, convex collider 80 tris, non-empty glTF. --skip-decimate exits 9; --stray-vert and --twin-sole exit 15; --lift-z exits 16; --clip-ring, --sunk-bands and --float-horseshoe exit 18; --short-post exits 19.",
       "hero": "docs/gallery/assets/hitching-post-hero.webp",
       "preview": "showcase/hitching-post/preview.webp",
       "tags": [
 
@@ -2,8 +2,8 @@
 
 A showcase piece, not an example. Procedural timber hitching post: a
 125 mm square post seated in a closed iron shoe, one cross-rail through
-the post, a pyramidal cap with eaves, and two rings hung through eyes
-under the rail. Then the shipped pipeline: unique-cell UVs, Cycles
+the post, a pyramidal cap with eaves, two rings hung through eyes
+under the rail, and a horseshoe nailed heels-up to the post's face. Then the shipped pipeline: unique-cell UVs, Cycles
 high-to-low normal bake, LOD chain, convex collider, Unity glTF export.
 
 It asserts **budget conformance** of the generated result. It does not
@@ -25,12 +25,12 @@ imported). Coplanar-pair counting matches `showcase/signpost`.
 Declared as named constants; every gate **recomputes** from the mesh,
 materials, UVs, evaluated LOD, collider, or export file.
 
-| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) |
+| Axis | Declared | Measured (4.5.11 / 5.2.1) |
 | --- | --- | --- |
-| Base triangles | 1400–2400 | 1680 / 1680 / 1680 |
-| LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 |
-| LOD2 ratio | 0.10–0.35 of base | 0.2190 / 0.2190 / 0.2190 |
-| Materials | exactly 2 distinct, ≥70 wood, ≥560 metal | 2 slots, 114 wood, 742 metal |
+| Base triangles | 1400–2400 | 1852 / 1852 |
+| LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 |
+| LOD2 ratio | 0.10–0.35 of base | 0.2192 / 0.2192 |
+| Materials | exactly 2 distinct, ≥70 wood, ≥560 metal | 2 slots, 114 wood, 828 metal |
 | UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 |
 | Outer AABB | (0.500, 0.149, 1.246) m ± 0.01 | (0.5000, 0.1490, 1.2460) |
 | Grounded zmin | within 1e-4 of 0 | 0 / 0 / 0 |
@@ -39,9 +39,10 @@ materials, UVs, evaluated LOD, collider, or export file.
 | Hung ring | centerline error ≤ 0.008 m, ring–wood overlap 0, eye–wood overlap 0, shank–ring overlap 0, shank bites the eye | 0, 0, 0, 0, 40 |
 | Shoe | each band overlaps the post, shoe overlaps the sole | band gap 0, sole–shoe 8 |
 | **Band seat** | each band above the shoe stands ≥ 0.004 m proud of the post faces | 0.00650 |
+| **Horseshoe seat** | exactly 1; back bites the post face 0.0005–0.004 m, face ≥ 0.004 m proud | 1, 0.00150, 0.00750 |
 | Wood–metal gap | BVH surface < 0.008 m | 0.00075 |
 | Collider tris | ≤ 280 | 80 |
-| Export | written, size > 0 | 127424 / 127424 / 127412 bytes |
+| Export | written, size > 0 | 139464 / 139452 bytes |
 
 Base triangles rose from **1598 to 1680**. The old rings were faceted
 tori clipped into the arm; the new eyes, shanks, and 24-segment hung
@@ -54,7 +55,26 @@ binaries agreed. Bake pixels are stochastic; the gate is `has_data`
 plus operator `FINISHED`, not byte-identity. Construction is
 closed-form; the only RNG is the seeded per-piece wood tone. Bevel inputs are sorted by edge index, so the face order is the same on
 every run; a Python set of edges handed to the bevel had made it vary.
-Export byte counts differ on 5.2.1 (glTF serializer), not a gated axis. Euler is 12 (six balls and seven tori) and is not gated to 2.
+Export byte counts differ on 5.2.1 (glTF serializer), not a gated axis. Euler is 14 (12 before the horseshoe added one more closed shell) and is not gated to 2.
+
+### Horseshoe
+
+A lone post with a stub rail read as the plainest object in the showcase
+lineup. A horseshoe nailed heels-up to the post's front face is what a
+real hitching post carries, and it is geometry, so it is budgeted: a
+flat iron bar (17 mm wide, 7.5 mm thick) swept around 290° of an arc,
+heels capped, centred on the post between the upper band and the rail
+and clear of the rings. Its back face bites the post face by 1.5 mm
+(`HS_BITE`); its face stands 7.5 mm proud. The shell classifier sets it
+apart from the hung rings, which are the same flat-loop shape class, by
+where it sits (on the post's centre line, not at ±`EYE_X`). **Horseshoe
+seat** reads the bite and the stand-off against the post's own front face
+off the mesh; `--float-horseshoe` pulls it 4 mm off the face and exits 18
+(bite −0.0025 m). It moved the budgets it should: base triangles 1680 →
+1852 (inside the declared 1400–2400) and metal faces 742 → 828. The outer
+AABB, collider (80 tris) and every other seat are unchanged. The hero key
+light rose from 660 to 960 W so the still sits in the calibration luma
+band.
 
 ### Bands, wood and stage
 
@@ -83,6 +103,7 @@ Each falsifier violates exactly one named budget. Proven on Blender
 | `--clip-ring` | Hung-ring centerline | 18 | ring_err 0.024, ring–wood overlap 32 |
 | `--short-post` | Seated post | 19 | post zmin 0.030 |
 | `--sunk-bands` | Band seat | 18 | band proud −0.0015 |
+| `--float-horseshoe` | Horseshoe seat | 18 | bite −0.0025 |
 
 Default exit is 0 on all three. `--clip-ring` also overlaps the rail;
 the centerline gate is the one that fires.
@@ -98,6 +119,7 @@ blender --background --python hitching_post.py -- --lift-z
 blender --background --python hitching_post.py -- --clip-ring
 blender --background --python hitching_post.py -- --short-post
 blender --background --python hitching_post.py -- --sunk-bands
+blender --background --python hitching_post.py -- --float-horseshoe
 blender --background --python hitching_post.py -- --output preview.webp --engine cycles
 ```
 
@@ -128,5 +150,5 @@ File-local. `9` is a valid check code. `10` is reserved for
 | 15 | Hygiene, including coplanar pairs (`--stray-vert`, `--twin-sole`) |
 | 16 | Grounded zmin (`--lift-z`) |
 | 17 | Wood–metal BVH gap above 8 mm |
-| 18 | Hung ring, shoe or band seat (`--clip-ring`, `--sunk-bands`) |
+| 18 | Hung ring, shoe, band or horseshoe seat (`--clip-ring`, `--sunk-bands`, `--float-horseshoe`) |
 | 19 | Post plumb, origin, and cup seat (`--short-post`) |
@@ -1,7 +1,8 @@
 """Game-ready hitching post — a showcase piece, not an example.
 
 Asserts budget conformance of a procedural timber hitching post (square
-post, pyramidal cap, cross-arm, iron shoe, bands, and hitching rings)
+post, pyramidal cap, cross-arm, iron shoe, bands, hitching rings and a
+face-nailed horseshoe)
 after composing shipped pipeline pieces: bmesh construction, UVs, two
 materials, high-to-low normal bake, LOD chain, convex collider, Unity
 glTF export.
@@ -15,7 +16,8 @@
 ring off the eye centerline. ``--short-post`` starts the post above the
 shoe cup so the seated-post budget fails. ``--sunk-bands`` builds the
 iron bands inside the post, as the piece first shipped, so the band-seat
-budget fails.
+budget fails. ``--float-horseshoe`` pulls the horseshoe off the post face
+so the horseshoe-seat budget fails.
 
 Construction is closed-form; the only RNG is the seeded per-piece wood
 tone. DECIMATE COLLAPSE triangle counts
@@ -79,6 +81,22 @@
 # corners broke the surface, as black slits. --sunk-bands restores that.
 BAND_BITE = 0.0015
 BAND_PROUD_MIN = 0.004
+
+# A horseshoe nailed to the post's front face, heels up for luck: a flat
+# iron bar swept around 290 degrees of an arc in the XZ plane. Its back face
+# bites the post face by HS_BITE and it stands HS_T proud of it. It sits
+# between the upper band and the rail, clear of the rings.
+HS_Z = 0.690
+HS_R_IN = 0.033
+HS_R_OUT = 0.050
+HS_T = 0.0075
+HS_BITE = 0.0015
+HS_OPEN_DEG = 70.0            # opening at the top, centred on +Z
+HS_STATIONS = 22
+HS_BITE_MIN = 0.0005
+HS_BITE_MAX = 0.004
+HS_PROUD_MIN = 0.004
+HS_FLOAT = 0.004              # --float-horseshoe pulls it off the face by this
 # Per-piece wood tone jitter and grain frequency, as in shipping-crate.
 PLANK_TONE_JITTER = 0.28
 TONE_SEED = 29
@@ -436,7 +454,7 @@ def _bvh(me, poly_ids):
 def seat_audit(me):
     """Recompute cup, hung-ring, and plumb budgets from the generated shells."""
     post = arm = cap = None
-    soles, rings, eyes, bands, shanks = [], [], [], [], []
+    soles, rings, eyes, bands, shanks, shoes_hs = [], [], [], [], [], []
     for idxs, polys in _face_shells(me):
         x0, x1, y0, y1, z0, z1 = _bounds(me, idxs)
         dx, dy, dz = x1 - x0, y1 - y0, z1 - z0
@@ -456,6 +474,10 @@ def seat_audit(me):
             continue
         if z0 < 0.004 and dz < 0.030 and dx > 0.10:
             soles.append(rec)
+        elif dy < 0.025 and dx > 0.06 and dz > 0.06 and abs(rec["c"].x) < 0.06:
+            # flat, face-mounted, on the post's centre line: the horseshoe
+            # (the hung rings are the same shape class but hang at +-EYE_X)
+            shoes_hs.append(rec)
         elif dy < 0.025 and dx > 0.06 and dz > 0.06:
             rings.append(rec)
         elif dx < 0.025 and dy > 0.025 and dz > 0.02:
@@ -485,6 +507,9 @@ def seat_audit(me):
         "shank_ring": 99,
         "shank_eye": 0,
         "band_proud": -1.0,
+        "horseshoes": len(shoes_hs),
+        "hs_bite": -1.0,
+        "hs_proud": -1.0,
     }
     if (
         post is None
@@ -544,6 +569,14 @@ def seat_audit(me):
         bx0, bx1, by0, by1, _bz0, _bz1 = _bounds(me, band["idxs"])
         band_proud = min(band_proud, 0.25 * ((bx1 - bx0) + (by1 - by0)) - post_half)
 
+    # Horseshoe seat, read against the post's own front face off the mesh:
+    # how deep its back bites into the post and how far its face stands out.
+    hs_bite = hs_proud = -1.0
+    if len(shoes_hs) == 1:
+        ys = [me.vertices[i].co.y for i in shoes_hs[0]["idxs"]]
+        hs_bite = max(ys) - post_y0
+        hs_proud = post_y0 - min(ys)
+
     pos, neg = [], []
     for i in arm["idxs"]:
         co = me.vertices[i].co
@@ -571,6 +604,8 @@ def seat_audit(me):
         "shank_ring": shank_ring,
         "shank_eye": shank_eye,
         "band_proud": band_proud,
+        "hs_bite": hs_bite,
+        "hs_proud": hs_proud,
     })
     return out
 
@@ -694,6 +729,28 @@ def add_torus(bm, center, major, minor, axis, mat_idx, n_major=24, n_minor=8):
     return made
 
 
+def add_horseshoe(bm, cz, y_back, y_front, mat_idx):
+    """Flat bar swept around the arc; rectangular section, capped heels."""
+    half_open = math.radians(HS_OPEN_DEG) * 0.5
+    a0 = math.pi * 0.5 + half_open
+    a1 = math.pi * 0.5 - half_open + 2.0 * math.pi
+    rings = []
+    for i in range(HS_STATIONS):
+        a = a0 + (a1 - a0) * i / (HS_STATIONS - 1)
+        ca, sa = math.cos(a), math.sin(a)
+        rings.append([
+            bm.verts.new((r * ca, y, cz + r * sa))
+            for r, y in ((HS_R_IN, y_back), (HS_R_OUT, y_back),
+                         (HS_R_OUT, y_front), (HS_R_IN, y_front))
+        ])
+    for r0, r1 in zip(rings, rings[1:]):
+        for k in range(4):
+            m = (k + 1) % 4
+            bm.faces.new((r0[k], r0[m], r1[m], r1[k])).material_index = mat_idx
+    bm.faces.new(tuple(reversed(rings[0]))).material_index = mat_idx
+    bm.faces.new(tuple(rings[-1])).material_index = mat_idx
+
+
 def build_hitching_post_mesh(
     name,
     bevel_offset,
@@ -703,6 +760,7 @@ def build_hitching_post_mesh(
     twin_sole=False,
     small_cap=False,
     sunk_bands=False,
+    float_horseshoe=False,
 ):
     """Post on a closed shoe, one rail, rings hung through eyes under the rail.
 
@@ -790,6 +848,12 @@ def build_hitching_post_mesh(
         for z in BAND_ZS:
             add_square_band(bm, z, band_in, BAND_T, BAND_H, METAL_IDX)
 
+        # the post's front face is flat across |x| < half - bevel, wider than
+        # the shoe; seat the shoe's back face HS_BITE inside it
+        hs_shift = -HS_FLOAT if float_horseshoe else 0.0
+        hs_back = -half + HS_BITE + hs_shift
+        add_horseshoe(bm, HS_Z, hs_back, hs_back - HS_BITE - HS_T, METAL_IDX)
+
         arm_bottom = ARM_Z - ARM_ZTH * 0.5
         eye_z = arm_bottom - EYE_MAJOR - EYE_MINOR - 0.004
         # Shank stops in the top of the eye tube. Continuing it to the eye
@@ -1135,6 +1199,7 @@ def check(
     clip_ring=False,
     short_post=False,
     sunk_bands=False,
+    float_horseshoe=False,
 ):
     bpy.ops.wm.read_factory_settings(use_empty=True)
     low = build_hitching_post_mesh(
@@ -1145,6 +1210,7 @@ def check(
         clip_ring=clip_ring,
         twin_sole=twin_sole,
         sunk_bands=sunk_bands,
+        float_horseshoe=float_horseshoe,
     )
     high = build_hitching_post_mesh(
         "HitchPostHigh", bevel_offset=0.008, bevel_segments=4, sunk_bands=sunk_bands,
@@ -1247,7 +1313,8 @@ def check(
         f"shank_ring={seat['shank_ring']} shank_eye={seat['shank_eye']} "
         f"parts={seat['post']}/{seat['arm']}/{seat['cap']}/"
         f"soles={seat['soles']}/rings={seat['rings']}/eyes={seat['eyes']}/bands={seat['bands']} "
-        f"band_proud={seat['band_proud']:.5f}"
+        f"band_proud={seat['band_proud']:.5f} horseshoes={seat['horseshoes']} "
+        f"hs_bite={seat['hs_bite']:.5f} hs_proud={seat['hs_proud']:.5f}"
     )
 
     if not (BASE_TRIS_MIN <= base_tris <= BASE_TRIS_MAX):
@@ -1354,14 +1421,19 @@ def check(
         or seat["shank_ring"]
         or seat["shank_eye"] < 1
         or seat["band_proud"] < BAND_PROUD_MIN
+        or seat["horseshoes"] != 1
+        or not (HS_BITE_MIN <= seat["hs_bite"] <= HS_BITE_MAX)
+        or seat["hs_proud"] < HS_PROUD_MIN
     ):
         return fail(
             f"hung ring / shoe seat ring_err={seat['ring_err']:.5f} "
             f"ring_wood={seat['ring_wood']} eye_wood={seat['eye_wood']} "
             f"band_gap={seat['band_gap']:.5f} sole_shoe={seat['sole_shoe']} "
             f"shank_ring={seat['shank_ring']} shank_eye={seat['shank_eye']} "
             f"band_proud={seat['band_proud']:.5f} (min {BAND_PROUD_MIN}) "
-            "(--clip-ring / --sunk-bands are the designed fails)",
+            f"horseshoes={seat['horseshoes']} hs_bite={seat['hs_bite']:.5f} "
+            f"(band [{HS_BITE_MIN}, {HS_BITE_MAX}]) hs_proud={seat['hs_proud']:.5f} "
+            "(--clip-ring / --sunk-bands / --float-horseshoe are the designed fails)",
             18,
         ), None, None, None, None, None
     if (
@@ -1437,8 +1509,8 @@ def light(name, loc, energy, size, col, rot):
         ob.rotation_euler = tuple(math.radians(a) for a in rot)
         scene.collection.objects.link(ob)
 
-    light("Key", (-3.6, -5.0, 5.4), 660.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36))
-    light("Fill", (5.0, -3.4, 2.4), 46.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50))
+    light("Key", (-3.6, -5.0, 5.4), 960.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36))
+    light("Fill", (5.0, -3.4, 2.4), 70.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50))
     light("Wedge", (2.2, 4.0, 3.8), 600.0, 5.5, (1.0, 0.70, 0.40), (-70, 0, 198))
 
     cam_data = bpy.data.cameras.new("Cam")
@@ -1525,6 +1597,11 @@ def main():
         action="store_true",
         help="falsification: bands inside the post, only the corners showing",
     )
+    p.add_argument(
+        "--float-horseshoe",
+        action="store_true",
+        help="falsification: pull the horseshoe off the post face",
+    )
     args = p.parse_args(argv)
 
     code, low, _high, wood, tex, _col = check(
@@ -1535,6 +1612,7 @@ def main():
         clip_ring=args.clip_ring,
         short_post=args.short_post,
         sunk_bands=args.sunk_bands,
+        float_horseshoe=args.float_horseshoe,
     )
     if code:
         return code