feat: add wooden-ladder and hay-bale showcase pieces

[TMHSDigital]

Summary

Prompt list 1–10 is exhausted. Next two ROADMAP items, shipped in that order:

• wooden-ladder — raked timber stiles, six rungs, iron shoes and straps
• hay-bale — bevelled straw loaf, end nap, two sisal twine belts

Picks named here because the standing-loop numbered list is empty. Restocked ROADMAP with wooden yoke and butter churn.

Wooden ladder

Composes skills mesh-editing-and-bmesh, bake-high-to-low, depsgraph-and-evaluated-data, engine-export-presets and snippets bake_normal_high_to_low.py, setup_bake_target_image.py, lod_chain.py / decimate_to_budget.py, convex_hull_collider.py, export_preset_unity.py (copied, not imported).

Falsifier --skip-decimate violates the LOD1 ratio budget (ratio 1.0, exit 9) on all three binaries.

Axis	Declared	4.5.11 / 5.1.2 / 5.2.1
Base tris	2100–2280	2184 / 2184 / 2184
LOD1	0.32–0.62	0.5000 / 0.5000 / 0.5000
LOD2	0.10–0.35	0.2198 / 0.2198 / 0.2198
Materials	2 distinct, ≥24 wood, ≥24 metal	1008 wood, 48 metal
UVs	0..1, overlap ≤ 1e-5	in range, overlap 0
Outer AABB	(0.474, 0.361, 1.482) ± 0.01	(0.4740, 0.3612, 1.4823), zmin 0
Collider	≤ 120	52
Export	size > 0	158256 / 158256 / 158240 B

Exit codes: default 0 / argparse 2 / --skip-decimate 9 on 4.5.11, 5.1.2, and 5.2.1. Same-binary rerun on 5.2.1 matched.

Added smoke wall-clock (check-only): 1.3s / 1.2s / 1.3s.

Hay bale

Same composed skills/snippets. Falsifier --skip-decimate violates LOD1 ratio (exit 9) on all three.

Axis	Declared	4.5.11 / 5.1.2 / 5.2.1
Base tris	220–290	252 / 252 / 252
LOD1	0.32–0.62	0.5000 / 0.5000 / 0.4683
LOD2	0.10–0.35	0.2143 / 0.2143 / 0.1429
Materials	2 distinct, ≥24 hay, ≥24 twine	66 hay, 60 twine
UVs	0..1, overlap ≤ 1e-5	in range, overlap 0
Outer AABB	(0.916, 0.520, 0.401) ± 0.01	(0.9160, 0.5200, 0.4010), zmin 0
Collider	≤ 120	68
Export	size > 0	25944 / 25944 / 25936 B

Exit codes: default 0 / argparse 2 / --skip-decimate 9 on all three.

Added smoke wall-clock (check-only): 0.8s / 0.9s / 1.1s.

DECIMATE COLLAPSE on the bale is leaner on 5.2.1; the gate is the ratio band. Export bytes differ by 8–16 B on 5.2.1 (serializer), not gated. Construction uses no RNG.

Evidence

Live run: check-only + falsifier + argparse on .scratch blender-4.5.11-windows-x64, blender-5.1.2-windows-x64, blender-5.2.1-windows-x64 (versions the binaries reported). Cycles 32-sample 1280×720 stills on 5.2.1; check_framing without deviation=; Pillow webp q=85 method=6.

Inspection only: gallery HTML alts after scripts/build_gallery.py (not truncated at dotted API paths).

Test plan

• needs-5.1 applied via REST; 5.1 smoke job present
• blender-smoke 5.2 LTS, 4.5 LTS, and labeled 5.1 all green
• Validate, drift-check, Socket green
• Squash-merge with branch deletion (no --admin)
• Post-merge: tag cut, Pages 200 for both gallery URLs